Metalworking Fluids Glossary

"S" Joint
A type of butt joint used to make a coated abrasive belt. The two ends of the belt material are cut in a "sine wave" pattern for more joint contact area.

Abrasive
Technically any material can be used to abrade another material. For industrial application, however, abrasives are minerals from a select group of very hard materials used to shape, finish, or polish other materials. In processes that grind, finish, polish, lap, or hone abrasives are typically limited to synthetic minerals with the exceptation of diamond and garnet. Common abrasive minerals appear in various crystalline forms of aluminum oxide, silcon carbine, zirconium oxide, diamond, and cubic boron nitride. As used in polishing or blast cleaning, an abrasive can be any substance used to remove material including ice, soild carbon dioxide, walnut shells, plastic, sand, or alumium oxide. Abrasives such as aluminum oxide, silcone carbine, and zirconia are typically called conventional abrasives due to their long history of use.

Abrasive Band
Diamond or other abrasive-coated endless band fitted to special band machine for machining hard-to-cut materials.

Abrasive Belt
A closed loop of coated abrasives used on tools that range from small hand-held equipment to very large machines that use belts five feet wide. Made by joining a strip of coated abrasive.

Abrasive Blast Cleaning
A process that uses a high-pressure stream of air or water to propel abrasive particles at the surface of a workpiece.

Abrasive Cut Off Saw
A thin resin bonded, reinforced grinding wheel used to saw or cut off metal from bar stock.

Abrasive Cutoff Disc
Blade-like disc with abrasive particles that parts stock in a slicing motion.

Abrasive Grains
The individual grits of abrasive mineral, also called grit, or abrasive mineral.

Abrasive Machining
Various grinding, honing, lapping, and polishing operations that utilize abrasive particles to impact new shapes, improve finishes, and part stock by removing metal or material.

Abrasive-Wire Bandsawing
A variation of bandsawing that uses a small-diameter wire with diamond, cubic-boron-nitride, or aluminum-oxide abrasives bonded to the surface as the cutting blade.

Absolute Filtration
A flitration system - typically "media separation" rather than gravity filtration where no particles larger than a stated size pass through the system: e.g. "5-micron absolute filtration" means that no particles larger than 5 micron pass through.

Absolute Viscosity
The ratio of shear stress to shear rate. It is a fluid's internal resistance to flow. The common unit of absolute viscosity is the poise. Absolute viscosity divided by fluid's density equals kinematic viscosity.

Acid number
The number of milligrams of potassium hydroxide requires to neutralize one gram of an oil sample.

Active Sulfur or Active Cutting Oil
Oils which in the presence of water causes copper (Cu) to stain. The color of the stain and its intensity are graded to measure its degree of activity. This grading is usually done in comparison with an ASTM standard where an A1 grade indicates least reactive oils and D5 the most.

Additive
Sulfur, chlorine, and other materials added to cutting fluids to improve lubricity, stabilize oil emulsions, and prevent chipwelding under high heat and pressure.

Admixture
Mixture of concentrate and water prepared to restore depleted cutting fluid to its original state.

Aging
A change in the properties of certain metals and alloys that occurs at ambient or moderately elevated temperatures after hot working or a heat treatment or after a cold working operatioin.

AGMA - American Gear Manufacturers Association
American Gear Manufacturers Association, which, as one of its activities, establishes and promotes standards for gears and gear lubricants.

AGMA lubricant numbers
AGMA specification covering gear lubricants. The viscosity ranges of the AGMA numbers (or grades) conform to the International Standards Organization (ISO) viscosity classification system.

Alclad
Composite wrought product comprised of an aluminum-alloy core having on one or both surfaces a metallurgically bonded aluminum or aluminum-alloy coating that is anodic to the core and thus electrochemically protects the core against corrosion.

Alkali Metal
A metal in group IA of the periodic system-namely, lithium, sodium, potassium, rubidium, cesium, and francium. It forms strongly alkaline hydroxides; hence, the name.

Alkaline-earth Metal
A metal in group IIA of the periodic system-namely, beryllium, magnesium, calcium, strontium, barium and radium - so called because the oxides or earths of calcium, strontium and barium were found by the early chemists to be alkaline in reaction.

Alloy
A substance having metallic properties and being composed of two or more chemical elements of which at least one is a metal.

Alloy Steel
Steel containing specified quantities of alloying elements within the limits recognized for constructional alloy steels, added to effect changes in mechanical or physical properties.

Alloying Element
An element which is added to a metal to change the metal's properties.

Alpha Iron
The body-centered cubic form of pure iron, stable below 910 degrees Celsius.

Alumel
A nickel-base alloy containing about 2.5Mn, 2Al, and Si used chiefly as a component of pyrometric thermocouples.

Alumina
Another term for aluminum oxide.

Aluminizing
Formation of an aluminum or aluminum-alloy coating on a metal by hot dipping, hot spraying, or diffusion.

Aluminum Oxide
The most common industrial mineral in use today. A synthetic form of the natural mineral corundum. Abrasive material for grinding tools.

Amorphous
Not having a crystal structure; noncrystalline.

Angle Plate
Solid adjustable or nonadjustable plate that holds work at a precise angle to the spindle during milling and grinding.

Aniline point
Lowest temperature at which equal volumes of aniline (a benzene derivative) is soluble in specified quanity of a petroleum product, as determined by test method ASTM D 611.

Annealing
In metallurgy and materials science, annealing is a heat treatment process where a material is altered, causing changes in its properties such as strength and hardness. It is a process that produces conditions by heating and maintaining a suitable temperature, and then cooling. Annealing is used to induce softness, relieve internal stresses, refine the structure and improve cold-working properties. In the cases of copper, steel, and brass this process is performed by substantially heating the material (generally until glowing) for a while and allowing it to cool slowly. In this fashion the metal is softened and prepared for further work such as shaping, stamping, drawing or machining.

Anneling
To reduce the hardness/stress of a material by “heat soaking” it and then allowing it to cool gradually. A careful heating and slow-controlled cooling cycle to reduce stress, refine the metals structure and reduce hardness.

Anode
The elctrode of an elctrolyte cell at which oxidation occurs.

Anodic Inhibitor
A chemical substance or mixture that prevents or reduces the rate of the anodic or oxidation reaction.

Anodic Protection
1. A technique to reduce the corrosion rate of a metal by polarizing it into its passive region, where dissolution rates are low. 2. Imposing an external electrical potential to protect a metal from corrosive attack.

Anodize or Anodizing
An electrical/electrochemical treatment for nonferrous metals, most typically aluminum, to control corrosion, impart color or make some other change in the surface of a material. It is in effect a controlled corrosion process.

ANSI - American National Standards Institute
An organization of industrial firms, trade associations, technical societies, consumer organizations, and government agencies, intended to establish definitions, terminologies, and symbols; improve methods of rating, testing and analysis; coordinate national safety, engineering and industrial standards; and represent U.S. interests in international standards work.

Antifoam
Something that prevents the formation of foam. Often used interchangeably with defoamer.

Antioxidant
Chemicals added to a coolant or oil to prevent or retard the oxidation of the product. This in turn reduces the amount of residue a product forms and makes the residue that is produced more easily cleanedup.

Antiwear Additive
Additive in a lubricant that reduces friction and excessive wear.

API - American Petroleum Institue
A trade association of petroleum producers, refiners, marketers, and transporters, organized for the advancement of the petroleum industry by conducting research, gathering and disseminating information, and maintaining cooperation between government and the industry on all matters of mutual interest.

Arbor
Shaft used for rotary support in machining applications.

Arc Cutting
The process of using an electric arc to sever, shape, saw, drill, and plane material. Usually assisted by some form of gas jet to help clear material from the cut.

Arc of Contact
The small portion of a grinding wheel where abrasives grains actually contact with the workpiece. This is the region where heat is generated during grinding and the effects of coolant critical.

Aromatic
Cyclic unsaturated hydrocarbons identified by one or more benzene rings or by chemical behavior similar to benzene.

Asperities
Microscopic projections on metal surfaces resulting from normal surface finishing processes.

Assembly
Joining together two or more parts to complete a structure.

ASTM - American Society for Testing and Materials
An organization devoted to 'the promotion of knowledge of the materials of engineering, and the standardization of specifications and methods of testing.

ATF Oil or ATF Fluid
Automatic transmission fluid used in the drives and clutches of some older machines. Easily emulsified by a coolant and may cause foam. ATF fluids often contain dye.

Atmospheric Corrosion
The gradual degradation or alteration of a material by contact with substances present in the atmosphere, such as oxygen, carbon dioxide, water vapor, sulfur, and chlorine compounds.

Atom
Anatom is the smallest particle characterizing a chemical element. An atom consists of an electron cloud surrounding a dense nucleus. This nucleus contains positively charged protons and electrically neutral neutrons, whereas the surrounding cloud is made up of negatively charged electrons. When the number of protons in the nucleus equals the number of electrons, the atom is electrically neutral; otherwise it is an ion and has a net positive or negative charge (sometimes referred to as valence). An atom is classified according to its number of protons and neutrons; the number of protons determines the chemical element and the number of neutrons determines the isotope of that element.

Automatic Bar Machine
Production machine for turning bar stock.

Automatic Chucking Machine
Machine with multiple chucks and toolholding spindles that permits either processing of several parts simultaneously or multiple machining steps in one pass through the machine.

Automatic Screw Machine
Turning machine designed to produce parts automatically from coil or bar stock. The two basic types are cam amd programmable.

Automatic Toolchanger
Automatic mechanism typically included in a machining center which, upon the appropriate command, will remove one cutting tool from the spindle nose and replace it with another.

Automation
Approach under which all or part of a machining or manufacturing process is accomplished by setting in motion a sequence that completes the process without further human intervention.

Axial Rake
On angular tool flutes, the angle between the tooth face and the axial plane through the tool point.

Back Rest
Support that mounts on a cylindrical grinder to prevent deflection when grinding long, small-diameter stock.

Backflash
A reactioin in dynamic motion systems where potential energy, which has been created while the object was in motion, is released when the object stops.

Backing
The flexible material to which abrasive grain is adhered to make coated abrasives and similar products. Typical backing materials are cloth/fabric, polyester film, or paper.

Backoff
Rapid withdrawl of tool from the workpiece.

Bactericides
Materials added to cutting fluid to inhibit bacterial growth.

Bainite
A metastable aggregate of ferrite and cemenite resulting from the transformation of austenite at temperatures below the pearlite range but above M. Its apperance is feathery if formed in the upper part of the bainite transformation range; acicular, resembling tempered martensite, if formed in the lower part.

Band Polishing
A variation of bandsawing that uses an abrasive band to smooth or polish parts previously sawed or filed.

Band Sawing
Power bandsawing, often called band machining, uses a long endless band with many small teeth traveling over two or more wheels in one direction.

Band Welder
Welder, normally mounted on the column of a contour band machine, that welds bandsaw blades to allow internal cuts.

Band-Bandsaw Blade
Endless band, normally with serrated teeth, that serves as the cutting tool for cutoff or contour band machines.

Banded Structure
A segregated structure consisting of alternating, nearly parallel bands of different composition, typically aligned in the direction of primary hot working.

Barrel Finishing
A mass finishing process. It involves low-pressure abrasion resulting from tumbling workpieces in a barrel together with an abrasive slurry.

Base Number
The number of milligrams of acid required to neutralize one gram of an oil sample.

Base Stock
A primary refined petroleum fraction, usually lubricating oil, into which additives and other products are blended to produce finished products.

Beach Marks
Progression marks on a fatigue fracture surface that indicate successive positions of the advancing crack front.

Bearing
Basic machine component designed to reduce friction between moving parts and to support a moving load.

Bending Machine
Machine designed to bend a workpiece to controlled, predetermined shape.

Bending Stress / Torsional Stress
Forces that tend to twist a material.

Bhn - Brinell hardness
Hardness scale used to indicate relative hardness of metals.

Biodegradation
The chemical breakdown of materials by living organisms in the environment.

Black Oxide
A black finish on a metal produced by immersing it in hot oxidizing salts or salt solutions.

Bleeding
Seperation of a liquid from lubricating grease.

Blending
A process of smoothing rough areas on a workpiece to ensure that their entire surface has close to the same plane or roundness and/or the same surface finish.

Blocks
Workholding devices used on milling machines. Styles include step, finger-holding, telescoping, and quick-clamp.

Blotter
A disc of compressible material used to cushion the contact between the slides of a grinding wheel and the flanges between which it is mounted to reduce slippage.

Blue Brittleness
Brittleness exhibited by some steels after being heated to a temperature within the range of about 200 degrees Celsius to 370 degrees Celsius, particulary if the steel is worked at the elevated temperature.

BOD - Biological Oxygen Demand
Biochemical Oxygen Demand (Biological Oxygen Demand) is an EPA test that measures the amount of dissolved oxygen consumed by microbial life during the decomposition of organic matter in waste water.

Bond
In grinding wheels the material used to hold abrasive grains in place giving shape to the grinding wheel, abrasive stick, hone, or similar products. Bonds are critical components of grinding wheels that help to distinguish one manufacturer from another.

Bonded Abrasive
Abrasive grains mixed with a bonding agent. The mixture is pressed to shape and then fired in a kiln or cured.

Boring
Enlarging a hole that already has been drilled or cored. Generally, it is an operation of truing the previously drilled hole with a single-point, lathe-type tool.

Boring Bar
Essentially a cantilever beam that holds one or more cutting tools in position during a boring operation.

Boring Cutter - Boring Tool
Cutting tool mounted in a boring bar (the holder) that enlarges a cored or drilled hole.

Boring Machine
Similar to a turning machine except that the cutting tool, rather than the workpiece, rotates to perform internal cuts.

Boron Carbide
A very hard material close in hardness to diamond.

Boundary Additives
Sulfur, chlorine, phosphorus, and other compunds. When added to cutting fluids, they fill in surface irregularities at the tool/workpiece interface, creating a lubricating film.

Boundary Lubrication
The most common type of lubrication found. It occurs when a highly charged layer, one-to-several molecules thick form on a surface or surfaces. These highly charged layers prevent or reduce surface-to-surface contact.

Brake Forming
The use of a pan brake to bend sheet metal. A brake may be manual, or it may be powered for heavier stock. A brake does not cut the metal as a shear does, but rather bends the stock into any perferred angle.

Brittle
Brittle materials fail suddenly, with little or no stretching. These materials fracture at 90o to the line of tension.

Brittle Fracture
Separation of a solid accompanied by little or no macroscopic plastic deformation.

Broach
Tapered tool, with a series of teeth of increasing length, that is pushed or pulled into a workpiece, successively removing small amounts of metal to enlarge a hole, slot, or other opening to final size.

Broaching
An operation in which a cutter progressively enlarges a slot or hole, or shapes a workpiece exterior.

Broaching Machine
Machine designed specifically to run broaching tools; typically designated by operating characteristics, type or power used, and tonnage ratings.

Bromine
Bromine is a chemical element with the symbol Br and an atomic number of 35. A halogen element, bromine is a red volatile liquid at standard room temperature that is intermediate in reactivity between chlorine and iodine. Bromine vapors are corrosive and toxic. Bromine is the only liquid nonmetallic element at room temperature and one of only six elements on the periodic table that are liquid at or close to room temperature. Bromine is a halogen, and is less reactive than chlorine and more reactive than iodine. Bromine is a powerful oxidizing agent. It reacts vigorously with metals, especially in the presence of water, as well as most organic compounds, especially upon illumination.

Bromine (Br) – Bromide (Br -)
A halogen sometimes found in industrial microbial compounds. It can be quite corrosive and has a very strong “bleaching” action.

Brookfield viscosity
A measure of the viscosity characteristics of a lubricant under low temperature and low shear conditions.

Brushing
Use of rapidly spinning wires or fibers to effectively and economically remove burrs, scratches, and similar mechanical imperfections from precision and highly stressed components.

Buffing
The process of obtaining a very fine surface finish, having a "grainless" apperarance on metal objects.

Builtup Edge or BUE
A layer of a workpiece material that is welded to the edge of the cutting tool. This BUE causes a change in the geometry of the cutting tool.

Burn
Thermal damage and physical changes in a workpiece caused excessive temperatures during grinding.

Burning
1. Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation. 2. In grinding, getting the work hot enough to cause discoloration or to change the microstructure by tempering or hardening.

Burnishing
A glazed surface finishing usually resulting from using a dull or loaded grinding wheel or coated abrasive.

Burr
The sharp edge that can result from machining or forming a mateial. Typically more severe when the material is ductile.

Bushing
An aloft metal like lead, babitt, or aluminum used to line the arbor holes of some grinding wheels. Also a removable ring, usually steel, used to adapt a grinding wheel to a smaller spindle.

CAD - computer-aided design
Product-design functions performed with the help of computers and special software.

CAE - computer-aided engineering
Engineering functions performed with the help of computers and special software.

CAM - computer-aided manufacturing
Use of computers to control machining and maunufacturing.

Cam-Cutting Attachment
Device for cutting face, peripheral, or cylindrical cams from flat cam-former stock.

Canned Cycle, fixed Cycle
Subroutine or full set of programmed numerical-control or computer-numerical-control steps, initiated by a single command.

Carbide
Compound of carbon and one or more metallic elements.

Carbon Equivalent or CE
While C and Fe are the major components that define cast iron both Si and P additions to the alloy can have similar effects on the cast iron recipe and the three materials can be traded back and forth to achieve specific results – in this context it is only important to understand that while the basic description of a cast iron is a ferrous alloy containing between 2% and 4% carbon. The inclusion of the CE concept expands the definition to between 2% and 6% CE content. CE = %C + 1/3 (%Si + % P)

Carbon residue
The measure of the coke forming tendency of oils at high temperatures.

Carbon Steel
Steel combined with varying amounts of carbon.

Carburizing
A heat treat process to increase the carbon content of the steel near the surface.

Carcinogen
A cancer-causing substance. Certain petroleum products are classified as potential carcinogens under OSHA criteria. Suppliers are required to identify such products as potential carcinogens on package labels and Material Safety Data Sheets.

Carriage Stop
Mechanical device placed on the lathe head or ways to prevent over-travel that might damage the machine or workpiece.

Case Hardening
A heat-treat process that increases the surface hardness of a steel part.

Cast
Cast is a manufacturing process by which a liquid material, such as a suspension of minerals used in ceramics, molten metal, or plastic is introduced into a mold, allowed to solidify within the mold, and then ejected or broken out to make a fabricated part.

Cast Alloy
Alloy cast from the molten state; most high-speed steel is melted in an electric-arc furnace and cast into ingots.

Cast Cobalt-based Alloy
Used to make turning tools for interrupted cuts; more heat resistant than high-speed steel and tougher (less brittle) than carbide.

Cast Iron
A family of iron (Fe) and carbon (C) alloys that contains between 2% and 4% carbon. Specific members of this family include gray iron, white iron, ductile iron, malleable iron, alloy iron, and CGI. Within each of these families are many different alloys.

Catalyst
A substance that contibutes to a chemical reaction without, itself, undergoing any change.

Cathode
The electrode of an electrolytic cell at which reduction is the principal reaction.

Cathodic Inhibitor
A chemical substance or mixture that prevents or reduces the rate of the cathodic or reduction reaction.

Cathodic Protection
1. Reduction of corrosion rate by shifting the corrosion potential of the electrode toward a less oxidizing potential by applying an external voltage. 2. Partial or complete protection of a metal from corrosion by making it a cathode, using either a galvanic or an impressed current.

Caustic Embrittlement
An obsolete historical term denoting a form of stress-corrosion cracking most frequently encountered in carbon steels or iron-chromium-nickel alloys that are exposed to concentrated hydroxide solutions at temperatures of 200 degrees Celcius to 250 degrees Celcius.

Cavitation
The formation of an air or vapor pocket (or bubble) due to lowering of pressure in a liquid, often as a result of a solid body, such as a piston, moving through the liquid; also, the pitting or wearing away of a solid surface as a result of the collapse of a vapor bubble.

Cavity Cutting
Machining entirely within the body of a workpiece.

CBN
Cubic Boron Nitride (also written as cBN). Boron nitride with a cubic crystalline structure which with diamond comprise the class of abrasives known as superabrasives. CBN is produced synthetically in a high temperature, high pressure process similar to synthetic diamond. CBN's primary value in grinding is for machining of ferrous materials which chemically react with diamond.

Cell Manufacturing
Grouping processes, equipment, and people together to manufacture a specific family of parts.

Cemented Carbide
Carbide manufactured using powder-metallurgy processes.

Center Drilling
Drilling tapered holes for mounting work between centers. Center-drilled holes also serve as preliminary "starter" holes for drilling larger holes in the same location.

Center Rest
Support provided at center of working area of cylindrical grinder to prevent part deflection during grinding.

Centerless Grinding
A grinding process named for a machine tool on which cylindrical workpieces are placed between a grinding wheel and regulating wheels. Primarily used in high production applications, centerless grinding has various forms that include through feed and plunge grinding.

Centers
Cone-shaped pins that support a workpiece by one or two ends during machining.

Ceramic
Made from finely powdered aluminum oxide sintered into the desired form.

Cermet
Material consisting of ceramic particles bonded with a metal. Cermets are more shock-resistant than ceramics.

Chamfering
Machining a bevel on a workpiece or tool to improve tool's entrance into the cut.

Chamfering Tool
Cutter or wheel that creates a beveled edge on a tool or workpiece.

Channel Point
A measure of the lowest temperature at which a gear lubricant may be used safely.

Chatter
A phenomena that produces periodic marks on the workpiece and is sometimes associated with audible sounds during grinding. It is caused by vibrations that originate with the rotating grindidng wheel, spindle, slides, or other components of the machine tools.

Chemical Coolant
A cutting fluid concentrate which contains no mineral oil.

Chemical Lubricity
Lubrication that is provided by the chemical reaction between chemicals in the metalworking fluid and the materials in the cutting zone (the work piece, the chip, and the cutting tool). See EP and boundary lubrication.

Chevron Pattern
A fractographic pattern of radial marks (shear ledges) that look like nested letters "V"; sometimes called a herringbone pattern.

Chill cast
Pouring molten metal into a mold that has been designed to rapidly cool or chill the material. This can be done by making the mold out of material that naturally and rapidly conducts heat away or by the introduction of “chills” (parts of the mold designed to serve as heat sinks) into the mold.

Chip
Small piece of material removed from a workpiece by a cutting tool.

Chipbreaker
Groove or other tool feature that breaks chips into small fragments as they come off the workpiece. Designed to prevent chips from becoming so long that they are difficult to control, catch in turning parts and cause safety problems.

Chlorinated wax
Certain solid hydrocarbons treated with chlorine gas to form straight-chain hydrocarbons with a realtively high chlorine component. Chlorinated waxes are used primarily as polyvinyl chlorine plasticizers, extreme-pressure additives for lubricants, and formulation components for many cutting fluids.

Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is a halogen, found in the periodic table in group 17 (formerly VIIa or VIIb). As the chloride ion, which is part of common salt and other compounds, it is abundant in nature and necessary to most forms of life, including humans. In its common elemental form (Cl2 or "dichlorine") under standard conditions, it is a pale green gas about 2.5 times as dense as air. It has a disagreeable, suffocating odor that is detectable in concentrations as low as 3.5 ppm and is poisonous. Chlorine is a powerful oxidant and is used in bleach and disinfectants. As a common disinfectant, chlorine compounds are used in swimming pools to keep them clean and sanitary. In the upper atmosphere, chlorine based molecules have been implicated in the destruction of the ozone layer

Chlorine (Cl)
A halogen element. Used in the metalworking fluid industry as an EP additive.

Chlorine (Cl) – Chloride (Cl-)
A highly reactive mono-valent anionic element. Most often of interest to us because of its use as an EP lubricity agent in metalworking fluids.

Chuck
Workholding device that affixes to a mill, lathe, or drill-press spindle. It holds a tool or workpiece by one end, allowing it to be rotated.

CIM - computer-integrated manufacturing
An approach under which all phases of production, from management to sales to order processing, design, quality control, and chipmaking, are controlled or monitored by interconnected computers.

Circular Saw
Cutoff machine utilizing a circular blade with serrated teeth.

Circulating Lubrication System
A system in which oil is recirculated from a sump or tank to the lubricated parts, in most cases requiring a pump to maintain circulation.

Clay filtration
A refining process using fuller's earth (activated clay), bauxite or other mineral to adsorb minute solids from lubricating oil, as well as remove traces of water, acids, and polar compounds.

Clearance
Space provided behind a tool's land or relief to prevent rubbing and subsequent premature deterioration of the tool.

Cleavage Fracture
A fracture, usually of a polycrystalline metal, in which most of the grains have failed by cleavage, resulting in bright reflecting facets.

Closed Coat
A characteristic of coated abrasives. A product is labelled as closed coated if abrasive grains cover more that 70 percent of the surface. Contrast with an open coated which has 50-75 percent coverage. Closed-coat products cut faster but can easily become loaded when used on soft materials.

Cloud Point
The temperature at which a lubricant appears hazy due to wax formation when a sample is cooled under standard conditions.

CNC - Computer Numberical Control
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts.

Coated Abrasive
Abrasive products made by adhering a thin layer of abrasive grains to a cloth, paper, or film backing.

Coated Tools
Carbide and high-speed steel tools coated with thin layers of aluminum oxide, titanium carbide, titanium nitride, hafnium nitride, or some combination of these.

COD
Chemical Oxygen Demand - an EPA test that measures the amount of dissolved oxygen to oxidize the chemical material in a waste water.

Coining
A closed-die squeezing operatioin in which all surfaces of the work are coined or restrained. Often imparts a pattern or shape onto the workpiece.

Cold Cranking Simulator
A viscometer used to predict the ability of an engine lubricant to allow cranking during cold starts.

Cold Rolled
A process where material (typically sheet, plate, or bar) is passed though a roll “stand” reducing (working the material) its thickness and increasing its hardness and yield strength. Cold-rolled material is normally “bright” as it is most often “pickled”. Cold-rolled stock is somewhat more consistent and easier to machine than is hot-rolled stock.

Cold Rolling
Is a metalworking process in which metal is deformed by passing it through rollers at a temperature below its recrystallization temperature. Cold rolling increases the yield strength and hardness of a metal by introducing defects into the metal's crystal structure. These defects prevent further slip and can reduce the grain size of the metal, resulting in Hall-Petch hardening. Cold rolling is most often used to decrease the thickness of plate and sheet metal.

Cold Shut
1. A discontinuity that appears on the surface of cast metal as a result of two streams of liquid meeting and failing to unite. 2. A lap on the surface of a forging or billet that was closed without fusion during deformation. 3. Freezing of the top surface of a ingot before the mold is full.

Cold Working
Deforming metal plastically under conditions of temperature and strain rate that induce strain hardening.

Collet
Flexible-sided device that secures a tool or workpiece.

Commercial-Grade Tool Steel
Low-grade tool steel; not controlled for hardenability.

Compacted Graphite Cast Iron
Cast iron having a graphite shape intermediate between the flake form typical of gray cast iron and the spherical form of fully spherulitic ductile cast iron.

Composites
Materials composed of different elements, with one element normally embedded in another, held together by a compatible binder.

Compounded Oil
A mixture of petroleum oil with animal or vegetable fat or oil. Compounded oils have a strong affinity for metal surfaces.

Concentrate
Agents and additives that, when added to water, create a cutting fluid.

Conductivity
An indirect measure of the amount, of minerals in a MWF system. It is the measure of a fluids ability to move electricity across a known gap through the fluid.

Cone Wheel
A small bonded abrasives wheel mounted on a pin or mandrel, typically cone- or bullet-shaped, or a similarl wheel made of coated abrasive strips wrapped around a mandrel. Both are used primarily on portable grinders.

Consistency (grease)
A basic property describing the softness or hardness of a grease, i.e., the degree to which a grease resists deformation under the application of force.

Constitution Diagram
A graphical representation of the temperature and composition limits of phase fields in an alloy system as they actually exist under the specific conditions of heating or cooling.

Contact Wheel
An essential component of machine tools designed for coated abrasives belts.

Continuous Casting
A casting technique in which a cast shape is continuously withdrawn through the bottom of the mold as it solidifies, so that its length is not determined by mold dimensions.

Contouring Attachment
Handwheel-operated mechanism for holding and guiding the work while sawing contours on a contour bandsaw.

Conventional Abrasive
A group of abrasives first introduced in the early 1900's to become the common abrasive used in wheels and coated abrasives. These include aluminum oxide and silcon carbine as well as aluminum oxide-zirconia abrasives. Ceramic abrasives, which are a recent innovation in abrasives, are a sintered microcrystalline form of aluminum oxide. Conventional abrasives contrast with superbrasives (CBN and diamond); abrasives that were developed and introduced to manufacturing during the second half of the 20th century.

Conversion Coating
A coating consisting of a compound of the surface metal, produced by chemical or electrochemical treatments of the metal.

Converter
A manufacturer that uses large jumbo rolls of coated abrasives as raw materials to make products such as belts, discs, sheets, etc.

Coolant
A term used to discribe a particular class of water soluble metal removal fluids which are used in machining and grinding to improve the metal removal process, improve surface integrity, move the chips out of the cutting zone, and provide in-process corrosion control.

Cooling - Cooling Capacity
The ability of a fluid to absorb and carry away heat from the cutting zone and the machine tool. Related to the fluid's specific heat and its ability to wet the surfaces.

Corrosion
Physicochemical interaction between a metal and its environment which results in changes in the properties of the metal and which may often lead to impairment of the function of the metal, the environment, or the technical system of which these form a part. ISO 8044-1986. Corrosion is an irreversible interfacial reaction of a material (metal, ceramic, polymer) with its environment which results in consumption of the material or in dissolution into the material of a component of the environment.

Corrosion
Chemical or electrochemical reaction between a material, usually a metal, and its environment that produces a deterioration (dimentional change) of the material and/or its properties.

Corrosion Fatigue
The process in which a metal fractures prematurely under conditions of simultaneous corrosion and repeated cyclic loading at lower stress levels or fewer cycles that would be required in the absence of the corrosive environment.

Corrosion Inhibitor
An additive for protecting lubricated metal surfaces against chemical attack by water or other contaminants.

Corrosion Resistance
The ability of a material to resist corrosion – primarily oxidation but not exclusively – in a specific and defined environment.

Corundum
A natural mineral whose principle composition is aluminum oxide. Corundum has been replaced by synthetic abrasive minerals which offer more uniform and consistent physical properties.

Counterbalancing
Use of weights or mechanisms to balance a workpiece, grinding wheel, rotating tool, or other device. Minimizes machining vibration and maximizes cutting force.

Counterboring
The process of enlarging one end of a drilled hole. The enlarged hole, which is concentric with the original hole, is flat on the bottom. Counterboring is used primarily to set bolt heads and nuts below the surface.

Countersinking
Cutting a beveled edge at the entrance of a hole so a screw head sits flush with workpiece surface.

Coupling Agent
A mutual solvent or an emulsifier.

Cratering
Depressions formed on the face of a cutting tool, caused by heat, pressure, and the motion of chips moving across the tool's surface.

Creaming
A concentration of oil droplets in an emulsion near the surface when it has stood quiescent for a sufficient period of time. It may indicate some level of emulsion instability. It is refered to as "creaming" because it is reminiscent of the cream layer found on the surface of whole milk before homogenization.

Creep
Time-dependent strain occurring under stress.

Creep Feed Grinding
A specialized grinding technique where large volumes of stock are removed with a few passes rather than many "lighter" passes used to grind the same part using conventional grinding techniques.

Crevice Corrosion
Corrosion that occurs as the result of “crevice geometry” and the resulting “highly corrosive” micro environment caused by a “stagnant electrolyte.”

Critical Cooling Rate
The rate of continuous cooling required to prevent undesirable transformation.

Critical Flaw Size
The size of a flaw (defect) in a structure that will cause failure at a particular stress level.

Crush Dressing
The process to dress and shape a grinding wheel by forcing it against a steel roll containing a desired profile.

Cryolite
A mineral containing sodium, aluminum, and fluorine that is added to some grinding wheels and coated abrasives as a solid lubricant grinding aid.

Crystal Structure/Lattice
The particular way that atoms are arranged to produce material. This structure has a great deal to do with how ductile or brittle a metal is. Heat treating of metals is largely about modifying these crystal structures. In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. A crystal structure is composed of a motif, a set of atoms arranged in a particular way, and a lattice. Motifs are located upon the points of a lattice, which is an array of points repeating periodically in three dimensions. The points can be thought of as forming identical tiny boxes, called unit cells, that fill the space of the lattice. The lengths of the edges of a unit cell and the angles between them are called the lattice parameters. The symmetry properties of the crystal are embodied in its space group. A crystal's structure and symmetry play a role in determining many of its properties, such as cleavage, electronic band structure, and optical properties

Cup Wheel
One of the standard wheel shapes standardized as types 6 and 11 in ANSI B7.1 Standards. With the shape of a cup, the products are designed for grinding on the rim or wall of the wheel rather that its periphery.

Curtain Application
Arrangement of multiple nozzles that apply fluid to a broad cutting area, as is found on a horizontal post-type band machine or a large hacksaw.

Cushioned Abrasive
Usually classed as a coated abrasive because it has a thin layer of abrasive on a flexible backing. This type of abrasive product contains a resilient layer of material added between the backing and abrasive grain. This highly flexible and conformable product is used in finishing and polishing metals and plastics such as Plexiglass.

Cutoff
Step that prepares a slug, blank or other workpiece for machining or other processing by separating it from the original stock.

Cutoff Blade
Blade mounted on a shank or arbor and held in a milling-machine spindle for simple cutoff tasks.

Cutoff Wheel
A common thin reinforced grinding wheel made with resin bond used for quick and efficient sawing of metal or masonary products.

Cutter Compensation
A feature that allows the opeartor to compensate for tool diameter, length, deflection, and radius during a programmed machining cycle.

Cutter Path
Path followed by the tool in machining the part.

Cutting Fluid
A fluid (liquid, gas, or a mist) applied to the tool work piece interface to promote more efficient material removal. Sometimes refered to as a coolant, cutting oil, or a metal removal fluid.

Cutting Oil
A cutting fluid, usually mineral oil, that is not designed to be diluted with water. In general these oils are not appropriate for lubrication.

Cutting Rate
The amount of material removed per unit of time or per unit of time per specific energy e.g., in 3 per min/HP.

Cutting Tool Materials
Include cast cobalt-based alloys, ceramics, cemented carbides, cubic boron nitride, diamond, high-speed steels, and carbon steels.

Cutting-Velocity Vector
Vector or direction the tool's cutting edge takes as a result of the interplay of forces applied and generated during the chipmaking process.

Cylinder Oil
A lubricant for independently lubricated cylinders, such as those of steam engines and air compressors; also for lubrication of valves and other elements in the cylinder area.

Cylindrical Grinding
One of several standard grinding processes used in the industry. Grinding to remove material from the OD of cylindrical parts that have been mounted on centers. Distinguished from centerless grinding which grinds the OD without center mounting.

Cylindrical Grinding Attachment
Device that mounts to the table of a surface grinder or lathe, permitting both straight and tapered grinding of round stock.

D&I or D&I Sheet
Data and Information sheet. The form that Master Chemical provides potential useful information to the "user and buyer."

Deburring
A process to remove burrs - undesirable protusions and metal edges that result from machining operations. Methods include hand automated processes that use files, rasps, bonded abrasives, coated abrasives, and other tools. Coated abrasives, nonwoven products and stones are typically used for deburring.

Defoamer
Materials that cause foam to collapse. Typically they float on the surface of the fluid and when they come in contact with the bubble, they reduce the surface tension of the bubble until the bubble collapses.

Deionization
Removal of ions from a water-based solution.

Demulsifier
An additive that promotes oil/water separation in lubricants that are exposed to water or steam.

Dendrite
A crystal that has a tree-like branching pattern, being most evident in cast metals slowly cooled through the solidification range.

Density
Mass-per-unit volume of a material.

Deoxidizing
1. The removal of oxygen from molten metals by use of suitable deoxidizers. 2. The removal of undesirable elements other than oxygen by the introduction of elements or compounds that readily react with them. 3. In metal finishing, the removal of oxide films from metal surfaces by chemical or electrochemical reaction.

Dermatitis
An unnatural or unususal condition of the skin.

Detergent
An important component of engine oils and some industrial lubricants, such as paper machine oils and hydraulic fluids; helps control deposits by preventing contaminants of combustion from directly contacting metal surfaces and, in some cases, by neutralizing acids.

Dezincification
Corrosion in which zinc is selectively leached from zinc-containing alloys.

DFA, design for assiembly
An engineering practice in which the designer of a part or assembly,while working with knowledgeable assembly people, designs the part or assembly to utilize a minimum of fasteners and require a minimum of labor hours.

Diamond
A natural and synthetic mineral composed of carbon atoms in a specific crystalline structure.

Diamond Bandsawing
Operation in which a band with diamond points is used to machine carbides, ceramics, and other extremely hard materials.

Die cast
A casting process where the molten metal is pushed into a permanent mold by pressure. Typically done for high-volume casting. Variations of the process include – centrifugal casting and squeeze casting.

Differential Aeration Cell
An electrolytic cell, the electromotive force of which is due to a difference in air (oxygen) concentration at one electrode as compared with that at another electrode of the same material.

Diffusion
1. Spreading of a constituent in a gas, liquid or solid, tending to make the composition of all parts uniform. 2. The spontaneous movement of atoms or molecules to new sites within a material.

Diffusion Coating
Any process whereby a basis metal or alloy is either: 1. coated with another metal or alloy and heated to sufficient temperature in a suitable environment. 2. exposed to a gaseous or liquid medium containing the other metal or alloy, thus causing diffusion of the coating or of the other metal or alloy into the basis metal with resultant changes in the composition and properties of its surface.

Disc Grinding
Grinding machines and processes using the face of a large wheel to produce flat and parallel surfaces in high-volume production. Single-wheel machines usually have a verticle spindle. Double-disc grinding passes parts between two independent grinding wheels.

Disc-Cutting Attachment
Adjustable device for a contour bandsaw that positions stock to allow sawing arcs and circular shapes on a contour bandsaw.

Discontinuous Yeilding
Nonuniform plastic flow of a metal exhibiting a yield point in which plastic deformation is inhomogeneously distributed along the gage length.

Dish
Form of relief given to the face of an endmill to prevent undesirable contact with the work.

Dispersant
An additive that helps prevent deposits by holding the insoluable products of oil oxidation and fuel combustion in suspension in the oil.

Dividing Head
Attaches to a milling-machine table and precisely indexes the workpiece.

DNC - Direct Numerical Control
Actions of multiple machine tools controlled by single computer.

DOT - Department of Transportaion
One of the organizations that regulates shipping either on a state and/or federal level.

Dovetail Cutter
Cutter for milling dovetail slots.

Draft
The angle on a mold that allows finished parts to be easily removed from a mold. Typically expressed as a angle, or as inches or fractions of inches per inch of depth This can be an issue because sometimes a cast part is substantially larger on one side than another as a result of the mold draft. This is particularly true when dealing with cored holes where the diameters and the hole at the top may be much larger than it is at the bottom. Often times because material is directly in contact with the surface of the mold or the core pin cools much more rapidly, there will be a difference in metallurgical structure and hardness as well.

Draw or Draw Down
A heat-treating process where the hardness of the material is reduced by carefully raising the temperature to the desired point and lowering it in a controlled manner to achieve the desired lower hardness.

Drawing
An operation wherein the work piece is pulled through a die, resulting in a reduction in outside dimensions. There are both cold and hot-drawn processes.

Dressing
To recondition a grinding wheel so that it grinds in the “proper manner.” Material dressed off of a grinding wheel is non productive and will not improve the G ratio.

Drill Jig
Accessory that holds a workpiece securely while guiding a drill or other tool into the workpiece; ensures accurate, repeatable location.

Drill-Grinding Gage
Used to check a drill's entry angle into a workpiece. Also used to check accuracy when grinding drills.

Drilling
Operations in which a rotating tool is used to create a round hole in a workpiece.

Drilling Machine or Drill Press
Machine designed to rotate end-cutting tools.

Drive Plate
Attaches to a lathe spindle; has a slot or slots that engage a driving dog to turn the work. Usually used in conjunction with centers.

Driving Dog
Device having a ring or clamp on one end that slips over the workpiece to be turned; a screw secures the workpiece in place.

Dropping Point
The temperature at which grease passes from a semi-solid to a liquid state as specified under ASTM D556.

Ductile
The ability of a material to plastically deform without fracture. Ductile materials fail by shear with much stretching before failure. They stretch a significant amount before failure with a significant reduction in the cross section of the material before failure, and they fail at a 45 angle to the tension. Examples of ductile materials include gold, aluminum, copper, low-carbon steel and rubber. Things like glass and ceramics are not very ductile while gold (Au) is the most ductile metal.

Ductile Cast Iron
A cast iron that has been treated while molten with an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherulites, which impacts a measurable degree of ductility to the cast metal.

Ductile Fracture
Fracture characterized by tearing of metal accompanied by appreciable gross plastic deformation and expenditure of considerable energy.

Ductility
The ability of a material to be bent, formed, or stretched without rupturing.

EBC - Electron Beam Cutting
A process related to laser-beam cutting or welding, but utilizing beam-spot intensities several orders of magnitude greater so complete vaporization occurs along the beam's path of travel.

EBM - Electron Beam Machining
Use of electrical energy to generate thermal energy for removing material.

Economies of Scale
Achieving low per-unit costs by producing in volume, permitting 'fixed costs" to be distributed over a large number of products.

Economies of Scope
Achieving low per-unit costs by computerizing production; allows goods to be manufactured economically in small lot sizes.

Edge Finder
Gage mounted in the spindle of a vertical mill and used, while rotating, to find the center of a part relative to the toolholder.

Elasticity
The property of a material to deform under stress and recover its original shape and dimensions after release of stress.

Elastohydrodynamic (EHD) Lubrication
A lubrication phenomenon occurring during elastic deformation of two nonconforming surfaces under high load.

Elastomer
A rubber or rubber-like material, both natural and synthetic, used in making a wide variety of products, such as seals and hoses.

Elastometer (seal) Compatibility
The quality of a lubricant to remain in contact with an elastomer without significantly affecting the chemical and physical properties of either.

Elastro Hydrodynamic Lubrication
Hydrodynamic lubrication where one or more of the "friction pairs" is flexable.

Electrical Insulating Oil
A high-quality, oxidation-resistant oil refined to give long service as a dielectric and coolant for electrical equipment, most commonly transformers.

Electrodeposition
The deposition of a substance on an electrode by passing electric current through an electrolyte.

Electroforming
A process for making thin parts whereby an electrode deposits metal on a mandrel or mold, which is subsequently stripped from the deposit. The process is simliar to electroplating, except that the deposit is substantially thicker than an electroplated deposit.

Electrohydraulic Forming
A method of shaping hollow tubes performed by discharging electrical energy inside the workpiece, which is filled with water or another suitable medium, producing shock waves that actually do the forming.

Electroplating
An electrical process for depositing metal on a conductive surface that uses a cathode in an electrolytic bath containing dissolved salts of the metal being deposited.

ELID
Electrolytic in-process dressing. A method to dress fine-grained superabrasive grinding wheels using an electrolytic method to dress metal bonded on grinding wheels. The process is an important new method to improve the efficiency of grinding ceramic and composite materials.

Elongation
In tensile testing, the increase in the gage length, measured after fracture of the specimen within the gage length, usually expressed as a percentage of the original gage length.

Embrittlement
Reduction in the normal ductility of a metal due to a physical or chemical change.

Emery
A natural abrasive that contains aluminum oxide and small amounts of iron oxide and is noted for its red color.

Emulsifiable Oil - Soluble Oil
A metalworking fluid concentrate that contains an emulsifier, or coupling agent and more than approximately 50% mineral or other oil so that the oil will form a stable emulsion in water.

Emulsifier
A material composed of bipolar molecules, one end of which is soluble in water and the other end in oil. These chemicals make it possible to mix to dissimilar insoluble liquids together; e.g., oil and water.

Emuslion
Suspension of one liquid in another, such as oil in water.

Emuslion Droplet or Particle Size
Refers to the size of the droplets that form the emulsion. Often refered to as loose, meaning course or large droplet size and tight, or fine, meaning small droplet size.

Endmilling
Operation in whch the cutter is mounted on the machine's spindle rather than on an arbor. Commonly associated with facing operations on a milling machine.

Endurance Limit
The maximum stress below which a material can presumably endure an infinite number of stress cycles.

EP (extreme pressure) Additivies
Cutting-fluid additives (chlorine, sulfur, or phosphorus compounds) that chemically react with the workpiece material to minimize chipwelding; good for high-speed machining.

EP Oil
A lubricating oil formulated to withstand extreme pressure (EP) operating conditions.

Erosion
Destruction of metals or other materials by the abrasive action of moving fluids, usually accelerated by the presence of solid particles or matter in suspension.

Ester
An organic chemical compound formed by the replacemnt of the hydrogen atom by an acid or by a hydrocarbon radical. Esters are commonly used in the formulation of metalworking fluids to provide boundary lubrication as they mimic the performance of fats.

Etching
1. Subjecting the surface of a metal to preferential chemical or electrolytic attack in order to reveal structural details for metallographic examination. 2. Chemically or electrochemically removing tenacious films from a metal surface to condition the surface for a subsequent treatment, such as painting or electroplating.

Ethane
A gasseous paraffinic hydrocarbon occuring in natural gas. Frequently used as a "feed stock" in the synthesis of other organic compounds.

Eutectic
An isothermal reversible reaction in which a liquid solution is converted into two or more intimately mixed solids on cooling, the number of solids formed being the same as the number of components in the system.

Exfoliation
A type of corrosion that progresses approximately parallel to the outer surface of the metal, causing layers of the metal to be elevated by the formation of corrosion product.

Explosive Forming
Shaping of metal parts wherein the forming pressure is generated by an explosive charge.

Extream Pressure Lubrication or EP Lubricity
The chemical change of one or more of the friction" (tribological) surfaces to form a thin film with a relatively low shear strength (relative to the tool or the work piece) that serves as a lubricating film.

Extruded
Material is pushed (extruded) or pulled (drawn) through a die to produce a part that has the cross section of the die profile and a length based on the amount of material available.

Extrusion
Is a manufacturing process used to create long objects of a fixed cross-sectional profile. A material, often in the form of a billet, is pushed and/or drawn through a die of the desired profile shape. Hollow sections are usually extruded by placing a pin or piercing mandrel inside of the die and in some cases positive pressure is applied to the internal cavities through the pin. Extrusion may be continuous (producing indefinitely long material) or semi-continuous (producing many short pieces). Some materials are hot drawn while others may be cold drawn.

Face Plate
Flat, round workholder with slots used to hold regular-or irregular-shaped stock.

Facemilling
A form of milling that produces a flat surface generally at right angles to the rotating axis of a cutter having teeth or inserts both on its periphery and on its end face.

Facing
Preliminary "cleanup" operation which provides a true reference surface before beginning another operation.

Family of Parts
Parts grouped by shape and size for efficient manufacturing.

Fatigue
The phenomenon leading to fracture under repeated or fluctuating stresses having a maxium value less than the tensile strength of the material.

Fatigue Life
The number of cycles of stress that can be sustained prior to failure under a stated test condition.

Fatigue Resistance
Ability of a tool or component to be flexed repeatedly without cracking; important for bandsaw-blade backing.

Fatigue Strength
The maximum stress that can be sustained for specified number of cycles without failure, the stress being completely reversed within each cycle unless otherwise stated.

Fatigue Striations
Parallel lines frequently observed by electron microscope fractographs of fatigue fracture surfaces.

Fatty Acid
Any of a series of saturate or unsaturated acide such as stearic, oleic and palmitic acids which occur in natural fats and natural oils. These compounds provide wetting, boundary lubrication, and emulsification.

Feather Burr
A very fine or thin burr.

Feather Edge
The same as a feather burr except that feather edge can also refer to a very thin machined ridge located at the ends of a lead-in or lead-out thread. It is sometimes called a wire edge or whisker-type burr.

Feed (grinding)
The amount that the wheel is advanced into the work piece for each pass.

Feed (Milling)
The maximum thickness of material removed with each milling tooth.

Feed (Turning)
The amount of horizontal movement of the tool per revolution of the work piece.

Feed Lines
The pattern produced on finished work surface by the cutting tool or grinding wheel e.g. the spiral mark left on a part by the turning tool or cylindrical grinding wheel.

Ferrite
A solid solution of one or more elements in body-centered cubic iron.

Ferritic Steel
A term usually applied to a group of stainless steels with a chromium content in the range of 12%- 18% and whose structure consists largely of ferrite. Such steels possess good ductility and are easily worked but do not respond to any hardening or tempering processes. Types of applications include automotive trim and architectural cladding.

Ferrography
A method of particle analysis using presicion magnets to strip iron-laden and other susceptible particles from a used lubricating oil for study; results indicate extent of equipment wear and likelihood of imminent failure.

File Bands
Segmented files mounted on an endless band for use on a powered band-type filing machine or on a contour-band machine with filing attachment.

Filiform Corrosion
Corrosion that occurs under some coatings in the form of randomly distributed threadlike filaments.

Filing
Operation in which a tool with numerous small teeth is used manually to round off sharp corners and shoulders and remove burrs and nicks.

Filing Attachment
Mounts on a contour bandsaw for power-filing operations.

Fillet
A rounded corner or arc that blends together two intersecting curves or lines.

Film Strength
Relative ability of a fluid to form a film between workpiece and tool, under the influence of temperature and pressure, to prevent metal-to-metal contact.

Fine Grinding
Machine tools and a grinding process for precision grinding of flat and parallel surfaces.

Finish
A measurement of surface characteristics of a workpiece.

Finish Feed
Feeding in small increments for finishing the part.

Finishing
Any of many different processes employed for surface, edge, and corner preparation, as well as conditioning, cleaning, and coating. In machining, ususally constitutes a final operation.

Finishing Cuts - Spark Out
The final passes that are made to optimize the final demenision and finish of the part. In grinding often refered to as the "spark out" pass where the infeed is stopped and grinding continues until sparks are no longer produced.

Finishing Tool
Tool, belt, wheel, or other cutting implement that completes the final, precision machining step/cut on a workpiece.

Fire Point
The temperature rating at which a lubricant will catch fire.

Fire-resistant fluid
A lubricant used especially in high-temperature or hazardous hydraulic applications, such as steel mills and underground mining.

Firing
The last step in manufacturing a vitrified or resin bond grinding wheel.

Fixture
Device, usually made in-house, that holds a specific workpiece.

Flakes
Short, discontinuous internal fissures in wrought metals attributed to stresses produced by localized transformation and decreased solubility of hydrogen during cooling after hot working.

Flame Cleaning
A method of cleaning metal parts by playing flames from an oxyacetylene torch over the surface to burn off oils, dry water residues, or heat scale rapidly and cause it to flake off.

Flank Wear
Reduction in clearance on the tool's flank caused by contact with the work. Ultimattely causes tool failure.

Flash
A thin web or film of metal on a casting which occurs at die partings, around air vents, and around movable cores.

Flash point
The minimum temperature at which a fluid will support instantaneous combustion (flash) but before it will burn continuously (fire).

Flat - Screw Flat
Flat surface machined into the shank of cutting tool for enhanced holding of the tool.

Flattening Die
Used to flatten hems; that is, dies that can flatten a bend by closing it.

Flint
An abrasive made from a natural mineral high in silicates.

Flood Application
Fluid applied in volume by means of a recirculating system comprised of a reservoir, filters, chip-removal components, pump hoses, and positionable application nozzles, along with movable splash shields, valves for adjusting flow, and other controls.

Flow Improver
An additive designed to modify wax crystal growth, thereby lowering the pour point and improving low temperature fluidity.

Flow Stress
The uniaxial true stress at the onset of plastic deformation in a metal.

Fluorine (F) – Fluoride (F-)
A highly reactive mono-valent anionic element and part of the halogen atomic family.

Flushing Hose
Hand-operated hose and nozzle added to a machine's cutting-fluid application system to permit manual flushing of table and workpiece areas.

Flutes
Grooves and spaces in the body of a tool that permit chip removal from, and cutting fluid application to, the point of cut.

Fluting
Cutting straight or spiral grooves in drills, endmills, reamers, and taps to improve cutting action and chip removal.

Fly Away Parts
Parts or components that become part of the aircraft and contribute to its ability to fly.

FMS - Flexible Manufacturing System
Automated manufacturing system designed to machine a variety of similar parts. System is designed to minimize production changeover time.

Foaming
A frothy mixture of air and a petroleum product (e.g., lubricant, fuel oil) that can reduce the effectiveness of the product, and cause sluggish hydraulic operation, air binding of oil pumps, and overflow of tanks or sumps.

FOG
Fats, oils and Greases - an EPA term for organic compounds sometimes found in waste water.

Follower Rest
A work rest or supporting device attached to the carriage that "follows" the cutting tool, keeping support near the point of cut.

Forge
Forging is the working of metal by plastic deformation. It is distinguished from machining, the shaping of metal by removing material, such as by drilling, sawing, milling, turning or grinding, and form casting, wherein metal in its molten state is poured into a mold, whose form it retains on solidifying. The processes of raising, sinking, rolling, swaging, drawing and upsetting are essentially forging operations although they are not commonly so called because of the special techniques and tooling they require. Forging results in metal that is stronger than cast or machined metal parts. This is because during forging the metal's grain flow changes into the shape of the part, making it stronger. Some modern parts require a specific grain flow to ensure the strength and reliability of the part. Many metals are forged cold, but iron and its alloys are almost always forged hot. This is for two reasons: first, if work hardening were allowed to progress, hard materials such as iron and steel would become extremely difficult to work with; secondly, most steel alloys can be hardened by heat treatments, such as by the formation of martensite, rather than cold forging. Alloys that are amenable to precipitation hardening, such as most structural alloys of aluminum and titanium, can also be forged hot, then made strong once they achieve their final shape. Other materials must be strengthened by the forging process itself.

Form Cutter
Cutter shaped to cut stepped, angular, or irregualr forms in the workpiece.

Form Grinding
Any grinding process where the surface of the grinding wheel is shaped by dressing to create a specific profile.

Form-Rolling Machine
Used to roll splines, gears, worms, and threads. A cold forming machine for production processing of previously machined parts.

Forming
Process in which material is stamped, stretched , bent, or given a new shape without intentionally removing material.

Fracture Stress
1. The maximum principal true stress at fracture. Usually refers to unnotched tensile specimens. 2. The (hypothetical) true stress that will cause fracture without further deformation at any given strain.

Fracture Toughness
The critical value (KIC) of stress intensity. A material property.

Free Abrasive Machining
Similar to a lapping process where loose abrasives are used to prepare precion flat surfaces.

Free-Machining Steels
Carbon and alloy steels that contain lead, sulfur, or other elements that improve machinability.

Fretting
A form of attritive wear resulting from small-amplitude oscillations or vibrations that cause the removal of very finely divided particles from rubbing surfaces.

Friability
A characteristic of abrasives grains that describes their tendency to fracture or break apart when hit or placed under pressure.

Friciton Sawing
Sawing with a special band machine capable of achieving band velocities of 15,000 sfm or more.

Friction
The resistance to the motion of one surface over another.

Friction Modifier
An additive designed to affect the frictional properties of rubbing surfaces.

Full-Fluid-Film Lubrication
The presence of a continuous lubricating film sufficient to completely separate two surfaces, as distinct from boundary lubrication.

Fungicide
Material added to chemical or soluble-oil cutting fluids to inhibit the growth of fungi and bacteria.

G Ratio
An expression of grinding wheel life calculated by dividing the amount of material removed from the work piece by the amount of wheel used. The calculation does not include wheel lost to dressing.

Galling
A condition whereby excessive friction between high spots results in localized welding with subsequent spalling and further roughening of the rubber surface(s) of one or both of two mating parts.

Galvanic – Galvanic Cell – Galvanic Series-
For our use these concepts refer to the flow of electrons from one metal to another when they are connected by an electrolyte. This is the way a dry cell battery works to produce DC electricity. When speaking of the galvanic series we are typically describing a list of material sorted by their potential to create electricity in a specific liquid ( typically “stagnate” sea water). These lists typically run from most “noble” to least noble.

Galvanic Corrosion
Corrosion that occurs because of the difference in relative position of materials on the galvanic scale. An electrochemical corrosion process between metals with different nobilities.

Gamma Iron
The face-centered cubic form of pure iron, stable 910 degrees Celsius to 1400 degrees Celsius.

Gang Cutting, Milling, Slitting
Machining with several cutters mounted on a single arbor, generally for simultaneous cutting.

Garnet
A natural mineral found in either igneous mineral deposits or in concentrated pockets of alluvial deposits of old river beds.

Gear
A machine part that transmits motion and force by means of successively engaging projections, called teeth.

Gear Cutter
Cutters designed for machining gears.

Gear Oil
A high-quality oil with good oxidation stability, load-carrying capacity, rust protection, and resistance to foaming, for service in gear housings and enclosed chain drives.

Gear Shaper
Machine that, in contrast to mills and hobbing machines, reciprocates the tool to cut the gear.

Gearbox (Gear Housing)
A casing for gear sets that transmits power from one rotating shaft to another.

Grade
Part of the standard grinding wheel making, indicating the relative hardness of the wheel bond structure. Though a universal standard has been establishe by ISO, there is no generally accepted measure of hardness in the United States. Manufacturers inidicate wheel grade with letters ranging from A for soft to Z for very hard. Since grade depends upon properties of bond materials, hardness values or one manufacturer may not correspond directly with simialr values from another manufacturer.

Grain Size
The second element in standard grinding wheel marking system or, in a more general meaning, the average size of abrasive size grains used to make a wheel, coated abrasive or other product.

Graphitic Corrosion
Deterioration of gray cast iron in which the metallic constituents are selectively leached or converted to corrosion products leaving the graphite intact.

Graphitization
A metallurgical term describing the formation of graphite in iron or steel, usually from decomposition of iron carbide at elevated temperatures. Not recommended as a term to describe graphitic corrosion.

Gray Cast Iron
A cast iron that gives a gray fracture due to the presence of flake graphite. Often called gray iron.

Grease (lubricating)
A mixture of a fluid lubricant (ususally petroleum oil) and a thickener (usually soap) dispersed in the oil.

Grinding
Machining with removing material from a workpiece by using abrasive minerals in a wheel, stone belt, paste, sheet, compound, slurry or other abrasive product.

Grinding Machine
Powers a grinding wheel or other abrasive tool for the purpose of removing metal and finishing workpieces to close tolerances.

Grinding Ratio
Ratio of work material removed to grinding-wheel material lost.

Grinding Wheel
Wheel formed from abrasive material mixed in a suitable matrix.

Grit Size
Specified size of the abrasive particles in grinding wheels and other abrasive tools. Determines metal removal capability and quality of finish.

Grooving
Machining grooves and shallow channels. Typically performed by tools that are capable of light cuts at high-feed rates; gives high-quality finish.

Group Technology
Classifying large numbers of different parts by characteristics before creating families of parts, with special consideration given to size.

Growth
In cast iron, a permanent increase in dimensions resulting from repeated or prolonged heating at temperatures above 480 degrees Celsius due either to graphitizing of carbines or to oxidation.

Guinier-Preston (G-P) Zone
A small precipitation domain in a supersaturated metallic solid solution. A G-P zone has no well-defined crystalline structure of its own and contains an abnormally high concentration of solute atoms.

Gundrilling
Drilling process using a single-lip, self-guiding tool to produce deep, precise holes. High-pressure coolant is fed to the cutting area, usually through the gundrill's shank.

H-Band Steel
Alloy steel produced to specified limits of hardenability; the chemical composition range may be slightly different from that of the corresponding grade of ordinary alloy steel.

Hacksaw - Power
Machine fitted with serrated blade held taut in a reciprocating frame that cuts in one direction, either on the forward or return stroke.

Halide – Halogen
A family of very reactive chemicals including: •fluorine (F), •chlorine (Cl), •bromine (Br), •iodine (I) •astatine (At) Chlorine is of major interest to the metal removal industry with bromine and iodine coming into play occasionally as components in biocides and as trace salts. It is thought that the presence of these ions will contribute to corrosion both as part of the electrolyte in a galvanic cell and as a cause agent in SCC, etc.

Halogens
The group of elements, chlorine, fluorine, bromine, and iodine.

Hard Chromium
Chromium electrodeposited for engineering purposes rather than as a decorative coating. It is usually applied directly to base metal and is customarily thicker than a decorative deposit, but not necessarily harder.

Hardenability
The relative ability of a ferrous alloy to form martensite when quenched from a temperature above the upper critical temperature.

Hardness
Resistance of metal to plastic deformation, usually by indentation. However, the term may also refer to stiffness or temper, or to resistance to scratching, abrasion, or cutting.

Hardness Tester
Tool designed to record the amount of pressure required to form an indentation in a material.

Hazzard Placards
Warning signs or labels placed on a truck or in a work area to advise that hazzardous materials are in use or being carried. Mandated by OSHA, DOT and other regulatory organizations.

Headchaning Machine
Like machining centers, this is a relatively new class of multifunction, numerical control machine tool.

Heat Treat
To change the mechanical and/or chemical characteristics of a metal by controlled heating and cooling.

Heat-Affected Zone
That portion of the base metal that was not melted during brazing, cutting, or welding, but whose microstructure and mechanical properties were altered by the heat.

HEDG
Like creepfeed grinding this process removes material from a workpiece in one or two passes using very slow table infeed rates.

Heeling - Heel Drag
Rubbing that occurs on the cutter's heel, the area just behind the tooth's cutting edge.

Helical Cutter
Endmill or other cutter with spiral or helical flutes. May be right or left handed.

Helix Angle
Angle the tool's leading edge makes with the plane of its centerline.

Hexane
A volatile liquid hydrocarbon solvent. This solvent is frequently used in labratory testing, e.g. the residue was soluble in hexane or the material was 25% hexane extractable.

High-Speed Milling Attachment
Device, typically combined with a universal milling attachment, that has gearing to turn small endmills at high speeds.

High-Speed Steel (HSS)
Tool steel alloyed with tungsten and molybdenum. Permits cutting at higher speeds and feeds than carbon steel tools because an HSS tool's cutting edges do not soften at temperatures which soften carbon steel.

HIP or HIPed -Hot isostatic pressing
The ability of a material to plastically deform without fracture. Ductile materials fail by shear with much stretching before failure. They stretch a significant amount before failure with a significant reduction in the cross section of the material before failure and they fail at a 45 degree angle to the tension. Examples of ductile materials include gold, aluminum, copper, low carbon steel and rubber. The ability of a material to deform plastically without fracture. Things like glass and ceramics are not very ductile while gold (Au) is the most ductile metal.

Hobbing
A gear-tooth-generating process consisiting of rotating and advancing a fluid steel worm cutter past a revolving bank.

Hobbing Machine
Machine in which a hob and blank rotate in precise relation to each other to create worm, spur, and helical gears and splines.

Hold-Down
T-slot bolt, strap clamp, or other device for securing workpieces to the machine tool.

Holemaking
Using a consumable tool such as a drill, reamer, punch, liquid medium, or electrode to produce holes in the workpiece.

Honing
Is a specific machining and finshing process usually applied to internal cylindrical surfaces using small bonded abrasive stones.

Honing Tool
Abrasive segments affixed to the periphery of a tool head and used to bring internal bores to an accurate, fine finish.

Hook
Concave shape on the face of a cutting edge or blade tooth that tends to pull the cutter or blade into the work.

Hot Corrosion
An accelerated corrosion of metal surfaces that results from the combined effect of oxidation and reactions with sulfur compounds and other contaminants.

Hot Crack
A crack formed in a cast metal because of internal stress developed on cooling following solidification.

Hot Isostatic Pressing, Hipping
A process for simultaneously heating and forming a powder metallurgy compact in which metal powder, contained in a sealed flexible mold, is subjected to equal pressure from all directions at a temperature high enough for sintering to take place.

Hot Rolled
A process where the metal is heated to a relatively high temperature (different for each alloy) and then the material is worked by rolling. With steel these materials are easily identified by their distinctive black oxide surface layer. Both because of the surface scale and the quenching rate, these materials tend to be more difficult to machine than cold rolled steel.

Hot Rolling
Is a metallurgical process used mainly to produce sheet metal or simple cross sections from billets. It is also used to describe the method of when industrial metal is passed or deformed between a set of work rolls and the temperature of the metal is generally above its recrystallization temperature, as opposed to cold rolling, which takes place below this temperature. Hot rolling permits large deformations of the metal to be achieved with a low number of rolling cycles. Because the metal is worked before crystal structures have formed, this process does not itself affect its microstructural properties. Hot rolling is primarily concerned with manipulating material shape and geometry rather than mechanical properties. This is achieved by heating a component or material to its upper critical temperature and then applying controlled load which forms the material to a desired specification or size. Mechanical properties of the material in its final 'as-rolled' form are a function of: material chemistry, reheat temperature, rate of temperature decreased during deformation, rate of deformation, heat of deformation, total reduction, recovery time, recrystallization time, and subsequent rate of cooling after deformation.

Hot Shortness
A tendency for some alloys to separate along grain boundaries when stressed or deformed at temperatures near the melting point.

Hot Tear
A fracture formed in a metal during solidification beacuse the shape of the object or the mold will not permit sufficient thermal contraction.

Hot Working
Deforming a metal plastically at temperature and strain rate such that the recrystallization temperature is exceeded and recrystallization takes place simultaneously with the deformation, thus avoiding any strain hardening.

Hydraulic Fluid
A fluid serving as the power transmission medium in a hydraulic system.

Hydraulic System
A system designed to transmit power through a liquid medium, permitting multiplication of force in accordance with Pascal's law, which states that "a pressure exerted on a confined liquid is transmitted undiminished in all directions and acts with equal force on all equal areas."

Hydrogen Damage
A general term for the embrittlement, cracking, blistering, and hydride formation that can occur when hydrogen is present in some metals.

Hydrogen Embrittlement
Sudden brittle fracture of high strength materials as the result of atomic hydrogen migrating into the material.

Hydrogenation
In refining, the chemical addition of hydrogen to a hydrocarbon in the presence of a catalyst; a severe form of hydrogen treating.

Hydrolic Oil
Typically a light oil intended to transmit power in hydraulic systems. These oils are normally highly formulated, and easily emulsified into coolant, where they can then contribute to foam, bacterial and residue problems.

Hydrolytic stability
The ability of a lubricant to resist chemical decomposition in the presence of water.

Hyrodynamic Lubrication
A lubrication regime where a liquid film separates the "friction pair." Sometimes referred to as full-film lubricaiton.

ID - Inner Diameter
Dimensions that define the inside of a part.

ID Grinding
A grinding process and machinery for grinding the inner diameter of holes or profiles using a very small, high-speed grinding wheel.

Immiscible
Incapable of being mixed without separation of phases. Water and petroleum oil are immiscible under most conditions, although they can be made miscible with the addition of an emulsifier.

Inclination Angle
Angle the cutter edge makes with a plane that is perpendicular to the direction of tool travel. Determines the direction of the chip curls.

Indexable Insert
Replaceable, geometric-shaped tool that clamps into a toolholder, drill, mill, or other cuttter body designed to accomodate inserts.

Indicator Drop Measurement
Method of determining if the primary and secondary reliefs on an endmill or other cutter have been properly grounded.

Induction Hardening
A surface-hardening process in which only the surface layer of suitable ferrous workpiece is heated by electomagnetic induction to above the upper critical temperature and immediately quenched.

Industrial Lubricant
Any petroleum or synthetic-based fluid or grease commonly used in lubricating industrial equipment, such as gears, turbines, and compressors.

Infrared (IR) Analysis
A form of absorption spectroscopy that identifies organic functional groups present in a used oil sample by measuring their light absorption at specific infrared wavelengths; absorbance is proportional to concentration.

Inhibitor
An additive that improves the performance of a petroleum product through the control of undesirable chemical reactions.

Inorganic Chemicals
Chemicals that do not contain carbon (C).

Insolubles
A test for contaminants in used lubricating oils, such as test method ASTM D 893.

Inspect, Do, Certify
This comes from the basic aircraft maintainers process where one person inspects a part; and if it is in need of maintenance, they fix or change it and then a second person comes along and “buys” the work by certifying that the work has been properly done.

Interchangeable Parts
Parts and components produced to specified tolerances, permitting them to be substituted for one another.

Intergranular Corrosion
Corrosion occuring preferentially at grain boundaries, usually with slight or negligible attack on the adjacent grains. Also called intercrystalline corrosion.

Internal Oxidation
The formation of isloated particles of corrosion products beneath the metal surface.

Interpolation
Process of generating a sufficient number of positioning commands for the servo motors driving the machine tool so the path of the tool will closely approximate the ideal path.

Interrupted Cut
Cutting tool repeatedly enters and exits the work; subjects tool to shock loading, making tool toughness, impact strength and flexibility vital.

Inverted or Invert Emulsion
A dispersion of water droplets into the oil. This typically results in a courser, less stable emulsion. An example of an invert emulsion is mayonnaise.

Investment Casting
1. Casting metal into a mold produced by surrounding (investing) an expandable pattern with a refractory slurry that sets at room temperature, after which the wax, plastic, or frozen-mercury pattern is removed through the use of heat. Also called precision casting or lost-wax process. 2. A part made by the investment casting process.

Iodine
Iodine is a chemical element that has the symbol I and atomic number 53. Naturally-occurring iodine is a single isotope with 74 neutrons. Chemically, iodine is the least reactive of the halogens, and the most electropositive halogen after astatine. However, the element does not occur in the free state in nature. As with all other halogens (members of Group VII in the Periodic Table), when freed from its compounds, iodine forms diatomic molecules (I2). Iodine and its compounds are primarily used in medicine, photography and in dyes. Although its high atomic number makes it rare in the solar system and earth's crust, the iodines are very soluble in water, and the element is concentrated in seawater. This mechanism helps to explain how the element came to be required in trace amounts by all animals and some plants, being by far the heaviest element known to be necessary to living organisms.

Iodine (I) – Iodide (I-)
The least reactive of the halogens typically found in the metalworking environment where it is sometimes used in the formulation of biocides and other organic compounds

Ion
A chemically charged atom •Cationic – positively charged •Anionic – negatively changed •Nonionic – having no charge

Ion
An ion is an atom or molecule which has lost or gained one or more electrons, making it positively or negatively charged. A negatively charged ion, which has more electrons in its electron shells than it has protons in its nuclei, is known as an anion . Conversely, a positively-charged ion, which has fewer electrons than protons, is known as a cation . An ion consisting of a single atom is called a monatomic ion, but if it consists of two or more atoms, it is a polyatomic ion. Polyatomic ions containing oxygen, such as carbonate and sulfate, are called oxyanions. Ions are denoted in the same way as electrically neutral atoms and molecules except for the presence of a superscript indicating the sign of the net electric charge and the number of electrons lost or gained, if more than one. For example: H+ and SO42−.

Ion Nitriding
A surface-hardening process in which nitrogen ions are accelerated under an electric potential in a closed chamber and become embedded in the surface of the parts being treated, where they interact with minor constituents of the treated metal to form nitrogen compounds.

ISO Viscosity Classification System
An international system, approved by the International Standards Organization (ISO), for clssifying industrial lubricants according to viscosity.

Isothermal Transformation
A change in phase that takes place at a constant temperature.

Jig
Tooling ususally considered to be a stationary apparatus. Jigs assist in the assembly or manufacture of a part or device.

Jig Boring
High-precision machining that orginially pertained to jig-and-fixture manufacturing.

Jig Grinder
A grinding machine tool for grinding molds and die where the positioining, shaping and finshing of holes and other surface is needed.

JIT - Just-In-Time
Philosophy based on identifying, then removing, impediments to productivity.

Jumbo Roll
A typical roll may be five feet wide and 50 yards long. These coated abrasive materials are used as raw materials by converters to manufacture belts, discs, sheets and other coated abrasive items.

Kerf
Width of cut left after a blade or tool makes a pass.

Keyseating
Milling or grinding an internal keyway.

Killed Steel
Steel treated with a strong deoxidizing agent such as silicon or aluminum to reduce the oxygen content so that no reaction occurs between carbon and oxygen during solidification.

Kinematic Viscosity
A measure of viscosity derived from the time taken for a fixed column of oil to flow through a capillary tube.

Knife-Line Hardness
Intergranular corrosion of an alloy, usually stabilized stainless steel, along a line adjoining or in contact with a weld after heating into the sensitization temperature range.

Knockout
A mechanism for releasing workpieces from a die; it is also called ejector, kickout, liftout, or shedder.

Knoop Hardness
Hardness rating for very thin materials and plated surfaces.

Knurling
Rolling depressions into the surface or a handle or similar part to provide a better gripping surface.

Knurling Tool
Normally a lathe tool for impressing a design on a rod or handle to improve gripping. May be either a cutting or forming operation.

Lap Joint
Property coated abrasives; a type of joint used to make a belt.

Lapping
A material removal process using loose abrasives and a fluid where parts are processed between two large flat lap plates to achieve very flat surfaces and extreme fine finishes.

Lathe
Turning machine capable of sawing, milling, grinding, gear-cutting, drilling, reaming, boring, threading, facing, chamfering, grooving, knurling, spinning, parting, necking, taper-cutting, and cam-and eccentric-cutting, as well as step- and straight-turning.

Lathe Turning
Machining operation in which a workpiece is rotated, while a cutting tool removes material, whether externally or internally.

Layout
Use of scribers, ink, and prick-punches to create a part to create a part outline that machinists use to visualy check part shape during machining of prototypes or during tool-and-die work.

Legacy , Parts, Processes and Products
Parts, processes and/or products that have proven to be successful in the past, and the customer chooses not to change them. “This is the way we have always done it in the past, and it isn’t worth changing now!”

Levitation Melting
An induction melting process in which the metal being melted is suspended by the electromagnetic field and is not in contact with a container.

Lip Angle
Included angle between a cutter's tooth and relieved land.

Load-Wear Index (LWI)
Measure of the relative ability of a lubricant to prevent wear under applied loads; it is calculated from data obtained from the Four Ball EP Method.

Loading
Deposits of workpiece material of the surface of a grinding wheel or coated abrasives that reduces contact between abrasives and workpiece.

Lost Wax Process
An investment casting process in which a wax pattern is used.

Low-Hydrogen Electrode
A covered arc welding electrode that provides an atmosphere around the arc and molten weld metal that is low in hydrogen.

Lubricant
Substance that reduces friction between moving machine parts. Can be liquid (hydrocarbon oil), solid (grease), or gaseous (air). Important characteristics are to prevent metal-to-metal contact between moving surfaces, be a cooling medium, and protect surfaces from rust and corrosion.

Lubricity
Measure of the relative efficiency with which a cutting fluid or lubricant reduces friction between surfaces.

Machinability
The relative ease (measured in tool life) of machining a material. Typically a reference steel (1212) is selected to represent the 100% reference, and materials that are more difficult to machine have lower numbers (D2 = 27%) and those easier to machine have higher (6061 = 380).

Machining
Process of giving a workpiece a new configuration by cutting or shaping it. Typically performed on a machine tool or machining center.

Machining Center
A computer-controlled machine tool capable of drilling, reaming, tapping, milling and boring.

Macro-Etching
Etching a metal surface to accentuate gross structural details for observation by the unaided eye or at a magnification of ten diameters or less.

Magnetic Chuck
Work-holding device used on surface grinders and milling machines for holding ferrous parts with large, flat sides.

Make Coat
The first layer of resin or adhesive applied to a flexible backing in the manufacture of coated abrasives.

Malleable Cast Iron
A cast iron made by prolonged annealing of white cast iron in which decarburization or graphitization, or both, take place to eliminate some or all of the cementite. The graphite is in the form of temper carbon.

Mandrel
Work holder for turning that fits inside hollow workpieces.

MAP - Manufacturing Automation Protocol
Standardized communication parameters that permit use of different brands of computer, software, and programming systems.

Martensite
Named after the German metallurgist Adolf Martens (1850–1914), is any crystal structure that is formed by displacive transformation, as opposed to much slower diffusive transformations. It includes a class of hard minerals occurring as lathe- or plate-shaped crystal grains. When viewed in cross-section, the lenticular (lens-shaped) crystal grains appear acicular (needle-shaped), which is how they are sometimes incorrectly described. "Martensite" most commonly refers to a very hard constituent of steel (the alloy of iron and carbon) important in some tool steels. The martensite is formed by rapid cooling (quenching) of austenite which traps carbon atoms that do not have time to diffuse out of the crystal structure.

Mass Finishing
A group of processes that use small stones of abrasives to remove burrs or apply a finish to small workpieces.

Master Alloy
An alloy, rich in one or more desired addition elements, that is added to a melt to raise the percentage of a desired constituent.

Material Safety Data Sheet (MSDS)
A publication containing helath and safety information on a product (including petroleum). The OSHA Hazard Communication Standard requires that an MSDS be provided by manufacturers to distributors or purcharsers prior to or at the time of product shipment.

Mechanical Lubricity
Where the fluid provides a physical barrier between the sliding material to prevent or reduce contact. See Hydrodynamic Lubrication.

Mechanical Plating
Plating wherein fine metal powders are peened onto the work by tumbling or other means.

Mechanical Properties
The properties of a material that reveal its elastic and inelastic behavior when force is applied, thereby indicating its suitability for mechanical applications.

Media
Abrasive pellets, stones, or other minerals used in mass finishing.

Metal Removal Factor
The volume of metal removal per unit of power in a given period of time.

Metalcutting - Material Cutting
Any machining process used to part metal, a material, or give a workpiece a new configuration.

Metalforming
Manufacturing processes in which products are given new shapes either by casting or by some form of mechanical deformation, such as forging, stamping, bending, etc.

Metallic Glass
A noncrystalline metal or alloy, commonly produced by drastic supercooling of a molten alloy, by electrodeposition, or by vapor deposition. Also called amorphous alloy.

Metallic Soap
The reaction product produced when a fatty acid reacts with metal.

Metallizing
1. The application of an electrically conductive metallic layer to the surface of nonconductors. 2. The application of metallic coatings by nonelectrolytic procedures such as spraying of molten metal and deposition from the vapor phase.

Metallography
The study of the grain structure of the metal after it has been cut, polished, mounted, and etched. This process is preformed to determine how the crystal (grain) structure was formed and to gather information about how the material may perform.

Metalworking
Any manufacturing process in which metal is processed or machined such that the workpiece is given a new shape.

Metalworking Lubricant
Any lubricant, ususally petroleum-based, that facilitates the cutting or shaping of metal.

Micelle
An aggregation of surface active molecules in solution.

Micro Inch
A unit of measure of length equal to one millionth of an inch, smaller than a micron since one inch is approximately 1/39th of a meter.

Micro-slicing
Cutting very small or thin parts from a larger base part. Uses a special machine witha thin, tensioned blade that takes a minimum kerf.

Microbicide
A chemical agent registered with the USDA as a biocide which destroys/kills bacteria. The term is sometimes used to include agents which destroy fungus and mold. These compounds are more correctly called fungicides.

Microhardness
The hardness of a material as determined by forcing an indenter such as a Vickers or Knoop indenter into the surface of the material under very light load; usually, the indentations are so small that they must be measured with a microscope.

Micron
A unit of measure equal to 0.000039 inches or 0.001mm.

Microstructure
The structure of a metal as revealed by microscopic examination of the etched surface of a polished specimen.

Mild Steel
Carbon steel with a maximum of about 0.25% carbon.

Milling
Machining operation in which metal or other material is removed by applying power to a rotating cutter.

Milling Arbor
Shaft or toolholder that inserts in the machine spindle and holds a peripheral-milling or face-milling cutter.

Mineral Oil
Any oil with a mineral origin e.g. petroleum oil as contrasted with animal, vegetable or synthetic oils.

Mineral Seal Oil
A distillation fraction between kerosene and gas oil, widely used as a solvent oil in gas adsorption processes, as a lubricant for the rolling of metal foil, and as a base oil in many specialty formulations.

Mischmetal
A natural mixture of rare-earth elements (atomic numbers 57 through 71) in metallic form. It contains about 50% cerium, the remainder being principally lanthanum and neodymium.

Miscible
Ability of a liquid to mix with another liquid.

Mist Application
Atomized fluid generally applied when a clear view of the cut point is needed, as in contour bandsawing or manual milling. The airborne mist can be directed precisely to the point of cut, cometimes reaching areas flood-applied coolant will not penetrate. The water evaporates on contact, providing further cooling, and leaves oils and additives on the work.

Mixture Ratio
Ratio of water to concentrate in certain cutting fluids.

Modern Design - Construction
Manufacturing of a product in subassemblies that permit fast and simple replacement of defective assemblies and tailoring of the product for different purposes.

Modular Fixturing
System in which fixtures are constructed from standardized, reusable components.

Modular Tooling
Tooling system comprised of standardized tools and toolholders.

Modulue of Elasticity
Measure of the relative elasticity or rigidity of a metal or material; established by stress/strain tests.

Mold (release) Lubricant
A compound, often of petroleum origin, for coating the interiors of molds for glass and ceramic products.

Molybdenum Disulfide
A black, lustrous powder that serves as a dry-film lubricant in certain high-temperature and high-vacuum applications.

Mounted Wheel or Mounted Point
A group of small abrasive wheel or cylindrical abrasive products whose shapes are defined by ANSI Standards. The abrasive products are made with a permanent shaft or mandrel and are typically bonded products, though some can be made with cotton or nonwoven fabric. Typically mounted points are used in internal grinding or de-burring processes.

MRV Viscosity
The measure of viscosity at low temperature and shear rate using a mini-rotary viscometer and designed to determine the ability of an engine oil to pump to critical locations immedidately following a cold start.

Multifunction Machines
Machines and machining/turning centers capable of performing a variety of tasks, including milling, drilling, boring, turning, and cutoff usually in just one setup.

Mutagenicity
The tendency of a substance to cause genetic mutations under long term exposure.

Naphthenic Oil
Petroleum fluid derviced from naphthenic crude oil, characterised by a high proportion of cyclo-parraffinic structures or by an absence of was molecules

Nascent
The condition of an element at the instant it is set free from a combination in which it has previously existed. The moment that the nascent condition is created is the point where the chemical or ion is going to be most active. For example the moment that the crystal structure of the metal is fractured the metal becomes very chemically active allowing it to react/activate the EP additives close to it.

NC - Numerical Control
Any controlled equipment that allows an oeprator to program its movement by punching in a series of coded numbers, symbols, etc.

Necking
Reducing the cross-sectional area of metal in a localized area by stretching.

Neo-Synthetic Fluid
Metalworking fluids with relatively low surface tension built with other than conventional surfactant chemistry. Many of these fluids contain "synthetic" or vegetable oils.

Newtonian Fluid
Any fluid, such as a straight mineral oil, whose viscosity does not change with rate of flow.

NIOSH
National Institute for Occupational Safety and Health – U.S. Department of Health and Human Services.

NLGI - Automotive Grease Classifications
Automotive lubricating grease quality levels established jointly by SAE, ASTM, and NLGI.

NLGI - Consistency Grades
Simplified system established by the National Lubricating Grease Institute for rating the consistency of grease.

NLGI - National Lubricating Grease Institute
Trade association whose main interest is grease and grease technology.

Noble Metal
1. A metal whose potential is highly positive relative to the hydrogen electrode. 2. A metal with marked resistance to chemical reaction, particularly to oxidation and to solution by inorganic acids. The term as often used is synonymous with precious metal.

Nominal Filtration
Is separation where some percentage of the stated size particles are retained by the system. Often times the percent of capture is not given.

Non-Newtonian Fluid
Fluid, such as a grease or a polymer-containing oil (e.g., multi-grade oil), in which shear stress is not proportional to shear rate.

Non-Silicone Defoamer
A conventional (topical) defoamer that does not contain diethylpolysiloxane. This type of defoamer does not create painting or plating problems when properly used.

Nontraditional Machining
Variety of chemical, electrical, mechanical, and thermal processes for machining workpieces.

Nonwoven abrasive
A product made with fine abrasive grains dispersed throughout a nonwoven fabric and adhered with resin.

Normal Paraffin
A hydrocarbon consisting of molecules in which any carbon atom is attached to no more than two other carbon atoms; also called straight-chain paraffin and linear paraffin.

Normal Stress
Normal stress is the forces acting normal to the material being stressed. Brittle materials tend to fail under normal stress.

Normalized or Annealing
A heat-treating process where the metal’s temperature is raised and then slowly lowered to release or normalize residual stress and make the material more ductile.

Notching
A stamping operation that cuts a piece of metal from the edge of a strip.

OD Grinding
Grinding of the outside diameter of cylindrical parts.

Off Hand Grinding
Using hand-held tools to grind. Also called free-hand grinding.

Oiler
A device for once-through lubrication.Three common types of oilers are: drop-feed, wick-feed, and bottle-feed; all depend on gravity to induce a metered flow of oil to the bearing.

Olefin
Any straight-chain hydrocarbon having one or more double (unsaturated) bonds.

Open Coat
A class coated abrasive product with 50% to 70% of the product surface covered with abrasive grains. Open coats are less likely to load when grinding soft materials though they are less efficient in material removal.

Open Gear
A gear that is exposed to the enivornment, rather than being housed in a protective gearbox.

Orange Peel
A surface roughening in the form of a pebble-grained pattern that occurs when a metal of unusually course grain size is stressed beyond its elastic limit.

Organic Chemicals
Chemicals which contain carbon (C).

Organic Compound
A chemical substance containg carbon and hydrogen. Other elements, such as nitrogen or oxygen, may also be present.

Orthogonal Chip Formation
Concentrated shear action at the point of cut that results in the formation of a continuous chip.

OSHA
Occupational Safety and Health Administration is a federal organization that regulates work place saftey.

Overshoot
Deviation from nominal path caused by momentum carried over from previous step, as when a tool is rapidly traversed a considerable distance to begin a cut.

Oxidation
The chemical combination of a substance with oxygen. All petroleum products are subject to oxidation, with resultant degradation of their composition and performance.

Oxidation Inhibitor
A substance added in small quantities to a petroleum or other product to increase its oxidation resisitance, thereby lengthening its service or storage life; also called antioxidant.

Oxidation Stability
The resistance of a petroleum product to oxidation; hence a measure of its potential service or storage life.

Paraffinic Oil
Paraffinic oils are more difficult to emulsify in water but are more oxidatively stable than naphtenic oil. Nearly all oils contain a mixture of napthenic and paraffinic oils.

Parallel
Strip or block of precision-ground stock used to elevate a workpiece, while keeping it parallel to the work table, to prevent cutter/table contract.

Particulates
Particles made up of a wide range of natural materials (e.g., pollen, dust, resins) combined with man-made pollutant (e.g., smoke particles, metallic ash); in sufficient concentrations particulates can be a respiratory irritant.

Parting
When used in lathe or screw machine operations, seperates a complete part from chuck-held or collect-fed stock by means of a very narrow, flat-end cutting tool. In metalforming, parting is a stamping operation that performs two cutoff operations in the same stroke, producing a small amount of scrap between successive blanks cut from a strip of metal.

Passivation
1. A reduction of the anodic reaction rate of an electrode involved in corrosion. 2. The process in metal corrosion by which metals become passive. 3. The changing of a chemically active surface of a metal to a much less reactive state.

Passivity
A condition in which a piece of metal, because of an impervious covering of oxide or other compound, has a potential much more positive than that of the metal in the active state.

Patina
The coating, usually green, that forms on the surface of metals such as copper and copper alloys exposed to the atmosphere. Also used to describe the apperance of a weathered surface of any metal.

PCB
Polychlorinated biphenyl, a class of synthetic chemicals consisting of a homologous series of compounds beginning with monochlorobiphenyl and ending with decachlorobiphenyl.

PCD - Polycrystalline Diamond
Natural or manufactured diamond crystals bonded together under high pressure at elevated temperatures; used for cutting nonferrous metals and nonmetallics.

Pearlite
A metastable lamellar aggregate of ferrite and cementite resulting from the transformation of austenite at temperatures above the bainite range.

Pedestal Grinder
A grinder with a motor and one or two grinding wheels on a floor pedestal.

Peening
Working of a metal by hammer blows or shot impingement.

Peripheral Milling
A form of milling that produces a finished surface generally in a plane parallel to the rotating axis of a cutter having teeth or inserts of the periphery of the cutter body.

Peripheral Speed
The speed of any point the surface of a moving part e.g. a rotating part, cutter, or grinding wheel. This is usually expressed in terms of SFPM (surface feet per miniute) or SMPM (surface meters per miniute).

Permanent Mold Casting
A casting process where the mold is used more than once. Die casting is the most common example of a permanent molding process.

pH
A measure of the acidity or alkalinity of an aqueous solution. The pH scale ranges from 0 (very acidic) to 14 (very alkaline) iwth a pH of 7 indicating a neutral solution equivalent tot ehpH of distilled water.

Phenol
A white, crystalline compound derived from benzene, used in the manufacture of phenolic resins, weed killers, plastics, and disinfectants; also used in solvent extraction, a petroleum refining process.

Phosphate Ester
Any of a group of synthetic lubricants having superior fire resistance.

Physical Properties
Properties of a metal or alloy that are relatively insensitive to structure and can be measured without the application of force.

Physical Vapor Deposition - PVD
Tool-coating process performed at low temperature, compared to chemical vapor deposition.

Pickled or Pickling
Is an acid washing process that makes cold-rolled steel “bright”. The pickling acid is most often diluted HCl and this process is the source for ferric chloride (FeCl3) which is often used in waste treatment to split soluble oils.

Piercing
The general term for cutting openings, such as holes and slots in sheets, plates, or parts.

Pitch
On a saw blade, the number of teeth per inch. In threading, the number of threads per inch.

Pitting
Localized corrosion of a metal surface, confined to a point or small area, that takes the form of cavities.

Planing
Machining operation that creates flat surfaces. The workpiece is reciprocated in a linear motion against one or more single-point tools.

Planing Bit
Cutting tool similar in apperarance to a turning tool, but with a longer shank.

Plasma Arc Spraying
The most versatile of the thermal spraying processes. In plasma arc spraying, coating material in wire or powder form is fed into the tip of a plasma arc torch, where it is melted and propelled against the substrate. Either the torch or the substrate is moved to provide controlled coverage of the target area.

Plastic Deformation
The permanent (inelastic) distortion of metals under applied stresses that strain the material beyond its elastic limit.

Plunge Grinding
Grinding of cylindrical parts in cylindrical or centerless grinding where the infeed of the grinding wheel is limited to removal movements and no cross-slide movement.

PM or Powdered Metallurgy
Process in which metallic particles are fused under variouus combinations of heat and pressure to create solid metals.

PM Sintered Bronze and Stainless steel
Are used as filter materials in applications requiring high temperature resistance while retaining the ability to regenerate the filter element. For example, sintered stainless steel elements are used for filtering steam in food and pharmaceutical applications.

PNA - Polynuclear Aromatic
Any of numerous complex hydrocarbon compounds consisting of three or more benzene rings in a compact molecular arrangement.

Point Angle
The included angle at the point of a twist drill or similar tool.

Point-to Point System
Numerical control system normally used for drilling and other operations where center-point location is readily determined.

Poise
A unit of measurement of absolute (or dynamic) viscosity.

Polar Additives
Animal, vegetable, or synthetic oils that, when added to a mineral oil, improve its ability to penetrate the work/tool interface.

Polar Compound
A chemical compound whose molecules exhibit electrically positive characteristics at one end and negativee characteristics at the other end.

Polishing
A process using very fine abrasive materials for little or no material removal where visual apperarance is the primary purpose.

Polishing Attachment
Abrasive grinding device that mounts on a contour bandsaw and uses fine-grit belts to grind and polish.

Polyester Film
A backing material for fine grained coated abrasives.

Polyglycols
Polymers of ethylene to proplylene oxides used as a synthetic lubricant base.

Polymer
A substance formed by the linkage (polymerization) of two or more simple, molecules, called monomers, to form a single larger molecule having the same elements in the same proportions as the original monomers; i.e. each monomer retains its structual identify.

Polyol ester
A synthetic lubricant base, formed by reacting fatty acids with a polyol (such as a glycol) derived from petroleum.

Polyolefin
A polymer dervied by polymerization of relatively simple olefins. Polyethelene and polyisoprene are important polyolefins.

Porosity
Open voids intentionally created in grinding wheels to provide pockets to carry swarf and metalworking fluids during grinding.

Pour Point
The temperature at which an oil begins to form a wax; i.e. not pour.

Pour Point Depressant
An additive used to lower the pour point of a petroleum product.

Powdered Metal (PM)
PM is a process for making solid metal parts by compacting metallic fines and then sintering them.

Power Brushing
Any process that uses a power-driven, rotary industrial brush to de-burr, clean, or finish a metal part.

Power Hacksawing
A sawing process that uses the back-and-forth motion of a short, straight-toothed blade to cut the workpiece.

ppb
Parts per billion

ppm
Parts per million

Precipitation Hardening
Hardening caused by precipitation of a constituent from a super-saturated solid solution.

Precipitation Hardening
Hardening caused by precipitation of a constituent from a super-saturated solid solution.

Press
A machine having a stationary bed and a slide which has a controlled reciprocating motion toward and away from the bed surface and at a right angle to it, the slide being guided in the frame of the machine to give a definite path of motion.

Press Brake
A special variation of the gap-type press especially delveloped for making long bends in sheet metal.

Press Forming
Any forming operation performed with tooling by means of a mechanical or hydraulic press.

Process Oil
An oil that serves as a temporary or permanent component of a manufactured product.

Productivity
Measure of the efficiency with which human and material resources are used to produce goods and services.

Profiling
Machining vertical edges of workpieces having irregular contours; normally with an endmill in a vertical spindle on a milling machine or with a profiler, following a pattern.

Pump
A mechanism through which force is applied to a liquid. There are two basic categories of pumps: positive displacement and centrifugal.

Punching
The cutting of holes, resulting in scrap slugs. It can be performed with punching presses specifically designed to hold the tooling or with stamping presses and unitized tooling.

Quenching Oil
A high-quality, oxidation-resistant petroleum oil used to cool metal parts during their manufacture, and is often preferred to water because the oil's slower heat transfer lessens the possibility of cracking or warping of the metal.

R & O - Rust-and-Oxidation Inhibited
A term applied to highly refined industrial lubricating oils formulated for lone service in circulating lubricatioin systems, compressors, hydraulic systems, bearing housing, gear boxes, etc. The finest R & O oils are often referred to as turbine oils.

Radial Drill
Large drill with an arm that pivots about a column to provide positioning flexability and greater reach and stability.

Rake
Angle formed between a tooth face and a line perpendicular to the cutter centerline.

Rancidity
Bacterial and fungal growths in water-miscible fluids that cause unpleasant odors, stained workpieces, and diminished fluid life.

Re-refining
A series of processes used to convert used oil into high-quality base-stock.

Reaming
A machining process that uses a multi-edge, fluted cutting tool to smooth, enlarge, or accurately size an existing hole.

RECRA
Resource Conservation and Recover Act, a federal law encouraging some types of recycling.

Recrystallization
Is a process by which deformed grains are replaced by a new set of undeformed grains that nucleate and grow until the original grains have been entirely consumed. Recrystallization is usually accompanied by a reduction in the strength and hardness of a material and a simultaneous increase in the ductility. Thus, the process may be introduced as a deliberate step in metals processing or may be an undesirable by, product of another processing step. The most important industrial uses are the softening of metals previously hardened by cold work, which have lost their ductility, and the control of the grain structure in the final product.

Recrystallization Temperature
The approximate minimum temperature at which complete recrystallization of a cold-worked metal occurs within a specified time.

Red Hardness
Ability of a cutting tool material to withstand high temperatures at the point of cut without softening and degrading.

Reduction of Area
1. Commonly the difference, expressed as a percentage of original area, between the original cross-sectional area of a tensile test specimen and the minimum cross-sectional area measured after complete seperation. 2. The difference, expressed as a percentage of original area, between original cross-sectioinal area and that after straining of the specimen.

Refactory Metal
A metal having an extremely high melting point. In the broad sense, this term refers to metals having melting points above the range of iron.

Refining
A series of processes for converting crude oil and its fractions to finished petroleum products.

Relief
Space provided behind the cutting edges to prevent rubbing.

Reserve Alkalinity
The ability of a product to maintain its working pH.

Residual Elements
Elements present in an alloy in small quantities, but not added intentionally.

Residual Stress
Stress (energy) retained in a work piece from earlier operation. This residual stress is often relived by secondary heat treating process like annealing or normalizing.

Resin Bond
A synthetic resin that can be cured by thermal, ultraviolet light, or other methods.

Rheology
The study of the deformation and flow of matter in terms of stress, strain, temperatures, and time. The rheological properties of a grease are commonly measured by penetration and apparent viscosity.

RIM - Reaction Injectioin Molding
A molding process which allows the rapid molding of liquid materials.

River Pattern
A term used in fractography to describe a characteristic pattern of cleavage steps running parallel to the local direction of crack propagation on the fracture surfaces of grains that have seperated by cleavage.

RMS
Root mean square method of measuring surface finish – one of many systems.

Rockwell Hardness or Rc
A type of hardness measurement using the Rockwell test instrument that dents the surface of the material with a penetrator. There are a vareity of different scales including the "A", "B" and "C" scales.

Roll Bending
A process for forming cylindrical or semicylindrical shapes from sheet or plate by feeding the work edgewise into the gap between a cluster for at least three relatively small-diameter straight rolls.

Roll Forming
A continuous process for forming metal from sheet, strip, or coiled stock into shapes of essentialy uniform cross section.

Rolling Oil
An oil used in hot or cold rolling of ferrous and nonferrous metals to facilitate feed of the metal between the work rolls, improve the plastic deformation of the metal, conduct heat from the metal, and extend the life of the work rolls.

Rotary Attachment
Bolts to a milling machine to permit machining such shapes as circular T-slots and cams.

Roughing Cutter, Tool
Tool for high-volume metal removal; normally followed by finishing passes.

RPM
Revolutions per minute.

Rubber Bond
A bond of synthetic or natural rubber used for grinding wheels and identified by the letter R in standard wheel markings.

Rust
A generic term for corrosion. It specifically refers to the product of the oxidation of ferrous (iron) compounds – often characterized as red or brown color.

Rust Inhibitor
A type of corrosion inhibitor used in lubricants to protect surfaces against rusting.

Rust Preventive
A compound for coating metal surfaces with a film that protects against rust; commonly used for the preservation of equipment in storage.

Sand Cast
A casting process where the molten metal to be cast is contained in a mold made of sand. The sand comes in many different forms. The key issue in sand casting is that the parts are not cooled as abruptly as in a permeate molding process and therefore the cast material has a more even microstructure. However, sometimes sand is transferred from the mold wall to the cast surface of the part. This sand can create interesting machining issues.

Saponification
The alkaline hydrolysis of fats to form a soap; more generally the hydrolysis of an ester by an alkali with the formation of an alcohol and a salt of the acid portion.

Saponification Number
The number of milligrams of potassium hydroxide (KOH) that combine with one gram of oil under conditions specified by test method ASTM D 94.

Sawing
Machining operation in which a powered machine, usually equipped with a blade having milled or ground teeth, is used to part material or give it a new shape.

Saybolt Universal Viscosity
The efflux time in Saybolt Universal Seconds (SUS) required for 60 milliliters of a petroleum product to flow through the calibrated orifice of a Saybolt Universal viscometer, under carefully controlled temperature, as prescribed by test method ASTM D 88.

Scalloping - Scallops
Wavy surface condition caused by deflection, unbalanced tool, loose workpiece or tooling, or a worn machine.

Scoring
Distress marks on sliding metallic surfaces in the form of long, distinct scratches in the direction of motion. Scoring is an advance stage of scuffing.

Scuffing
Localized distress marks on sliding metallic surfaces, appearing as a matte-finished area rather than as individual score marks.

Seal Swell
The swelling of rubber gaskets, or seals, when exposed to petroleum, synthetic lubricants, or hydraulic fluids.

Segments
Bonded wheel structures that can be assembled on a special form to create a large grinding wheel.

Selective Leaching
Corrosion in which one element is preferentially removed from an alloy, leaving a residue (often porous) of the elements that are more resistant to the particular environment.

Semisynthetic Coolant or Semichemical Coolant
A cutting fluid concentrate that contains a small amount of mineral oil. Typically those containing between 2% and approximately 20% are referred to as low-oil semisynthetics, those with more than 20% but less than 50% are referred to as high-oil semisynthetics or microemulsions.

Sensitization
In austenitic stainless steels, the precipitation of chromium carbides, usually at grain boundaries, on exposure to temperatures of about 550 degrees Celcuis to 850 degrees Celcuis, leaving the grain boundaries depleted of chromium and therefore susceptible to preferential attack by a corroding medium.

SFPM -Surface Feet Per Minute
How rapidly a point on the surface of a rotating tool or work piece moves in a minute. Most often calculated using the general formula SFPM= effective diamiter in inches x RPM/3.82.

Shank
Main body of a tool; the portion of a drill or similar end-held tool that fits into a collect, chuck, or similar-mounting device.

Shaping
Using a shaper primarily to produce flat surfaces in horizontal, vertical, or angular planes.

Sharper Tool
Single-point tool that traverses workpiece in a reciprocating fashion to machine a desired shape.

Shaving
Cutting off metal in a chip fashion to obtain accurate dimensions and also to remove the rough, fractured edges of sheet metal.

Shear Forming
Also known as flow turning, is similar to spinning, but during flow turning the metal is intentionally thinned by shear forces.

Shear Lip
A narrow, slanting ridge along the edge of a fracture surface. The term sometimes also denoted a narrow, often crescent-shaped, fibrous region at the edge of a fracture that is otherwise of the cleavage type, even though this fibrous region is in the same plane as the rest of the fracture surface.

Shear Plane
Plane along which the chip parts from the workpiece.

Shear Rate
The rate at which adjacent layers of a fluid move with respect to each other, usually expressed as reciprocal seconds.

Shear Strength
The stress required to produce fracture in the plane of cross section, the conditions of loading being such that the directions of force and of resistance are parallel and opposite although their paths are offset a specified minimum amount.

Shear Stress
Shear stresses are the forces acting parallel to the surfaces being stressed. Ductile materials tend to fail under shearing stress.

Shearing
A process by which large sheets of material are cut into pieces of specified length and width.

Shock Loading
Tool is subjected to sudden, heavy loads and/or impacts, as in interrupted cutting.

Shop Air
Pressurized air system that cools the workpiece and tool when machining dry. Also refers to central pneumatic system.

Shot Blasting
Blasting with metal shot; usually used to remove deposits or mill scale more rapidly or more effectively than can be done by sand blasting.

Shot Peening
Cold working the surface of a metal by metal-shot impingement.

Shrinkage
The percent smaller that the finished cold blank is than the mold that it was cast in. or the reduction in size seen when a PM part is sintered. The shrinkage number is usually expressed as a percent shrink.

Sigma Phase
A hard, brittle, nonmagnetic intermediate phase with a tetragonal crystal structure, containg 30 atoms per unit cell, space group P42/mnm, occuring in many binary and ternary alloys of the transition elements.

Silicone
The trade marked name of dimethylepolysiloxane. These compounds are often use as defoamers in metalworking fluids. When used this way they are most often applied as an emulsion.

Single-Crystal Diamond
Industrial grade, natural diamond. Not recommended for cutting ferrous materials because it tends to react chemically with them and break down. Also not recommended for interrupted cuts in hard materials.

Sintered
To fuse powdered particles together by raising the material temperature to just below the melting point so that the particles join or bond on the most basic levels. Sintering is a method for making objects from powder, by heating the material (below its melting point) until its particles adhere to each other. Sintering is traditionally used for manufacturing ceramic objects, and has also found uses in such fields as powder metallurgy. In most cases the density of a collection of grains increases as material flows into voids, causing a decrease in overall volume. Mass movements that occur during sintering consist of the reduction of total porosity by repacking, followed by material transport due to evaporation and condensation from diffusion. In the final stages, metal atoms move along crystal boundaries to the walls of internal pores, redistributing mass from the internal bulk of the object and smoothing pore walls. Surface tension is the driving force for this movement.

Size Coat
A second coating of resin or adhesive applied during the manufacture of coated abrasives to improve adhesion of abrasive grain.

Slicing, Slitting
Cutting along single lines.

Slotting
Machining, normally milling, that creates slots, grooves, and similar recesses in workpieces, including T-slots and dovetails. Also a punching operation in which elongated and rectangular holes are cut.

Slotting Attachment
Converts a milling machine's rotary spindle motion into a reciprocatinig motion for machining keyways and slots.

Soft - Green - Pre Sintered Parts
Powdered material that has been pressed together into a form before sintering. PM parts are said to be soft, green or presintered after they are pressed or shaped but before sintering. The parts are held together either by mechanical packing or some sort of wax or oil blended into the powder. Such powder is said to be lubricated.

Soluble Oil
A metalworking fluid concentrate that contains an emulsifier, or coupling agent and more than approximately 50% mineral or other oil so that the oil will form a stable emulsion in water.

Solution Treated or Solution Hardening
A heat-treating method (can be either hardening or annealing) used on metal’s (primarily aluminum the W, T3, T4, T6, T7, and T6 treatments) by submersing into salts and liquids. This very carefully controlled process allows for the maximization of a selected crystal structure.

Solvent
A material with a strong capability to dissolve a given substance. The most common petroleum solvents are mineral spirits, xylene, toluene, hexane, heptane, and naphthas.

Solvent Extraction
A refining process used to seperate components from lube distillates in order to improve the oil's oxidation stability, viscosity index, and response to additives.

Spade Drilling
Drilling operation in which a machine powers a cutting tool consisiting of a holder and flat, interchangeable endcutting blades.

Spar Mill
Machine tool designed to machine very large forgings to produce spars and ribs. Sometimes referred to has an Onsrude mill for the company that originally made them and most of the cutters used on these machines.

Spars and Ribs
The structural components that support the structure of the air frame. The names come from ship building and go back to when aircraft were made primarily from wood.

Speciality Coated Abrasives
A group of small converted coated abrasives that include cylinders, cones, pugs, flap wheels, etc. Typically these items are applied with hand tools for a variety of finishing and deburring applications.

Specific Cutting Energy
Measure of the total energy required to make the cut, including the energy needed to part the stock and over some frictional forces generated during cutting.

Spectrographic Analysis - Elemental Analysis
A technique for detecting and quantifying metallic elements resulting form wear, contamination, or additives.

Spindle Adapters
Bushings or toolholders that permit affixing a variety of taper-and straight-shank tools to a machine spindle.

Spindle Finishing
A mass finishing process in which workpieces are individually mounted on spindles, then lowered into a rotating tub containing the finishing media.

Spindle Oil
A low-viscosity oil of high quality for the lubrication of high-speed textile and metalworking (grinding) machine spindles.

Spinning
A chipless production method of forming axially symmetrical metal shapes.

Spiral Milling
Milling while simultaneously rotating and feeding the workpiece to create a spiral form.

Sponge
A form of metal characterized by a porous condition that is the result of the decomposition or reduction of a compound without fusion.

Spotfacing
Similar to counterboring except that in spotfacing, material around the original hole is cut.

Staining
A chemical change on the surface of a part that does not physically change the size of the part. Stains typically have smooth flowing edges while corrosion spots typically have rough edges.

Statistical Process Control (SPC)
The use of control charts to track and eliminate variables in repetitive manufacturing processes, in order to ensure that the product is of consistent and predictable quality.

Steady Rest
Supports long, thin, or flexible work being turned on a lathe. Mounts on the bed's ways and, unlike the follower rest, remains at the point where mounted.

Stearate
A salt or ester of stearic acid.

Steel
Is an alloy of iron (Fe) and less than 2% carbon (C). Other metals may be added to create alloy steel.

Steel-Specification Number
A system of numbers developed by the AISI and SAE to identify steel.

Stick-slip Motion
Erratic, noisy motion characteristic of some machine ways, due to the starting friction encountered by a machine part at each end of its back-and-forth movement.

STLE - Society of Tribologists and Lubrication Engineers
A technical organization intended to advance the knowledge and application of lubrication and related sciences.

Straight Mineral Oil
Petroleum oil containing no additives.

Straight Oil
A cutting fluid that is not intended to be diluted with water. Originally it implied that the cutting oil had nothing but oil in it e.g. no additive systems.

Straight-Cut System
Numerical-control system wherein tools move at 45 or 90 degree angles to the coordinate axes.

Strain Hardening
An increase in hardness and strength caused by plastic deformation at temperatures below the recrystallization range.

Stress
Stress is the average amount of force applied per unit area e.g. psi as pounds per square inch, Pa or MPa for Newtons per/m2 or mega Newtons/m2. It can also be thought of as energy stored in or applied to a material.

Stress corrosion cracking (SCC)
Stress corrosion cracking (SCC) is the unexpected sudden failure of normally ductile metals or tough thermoplastics subjected to a constant tensile stress in a corrosive environment, especially at an elevated temperature (in the case of metals). This type of corrosion often progresses rapidly. The corrosive environment is of crucial importance, and only very small concentrations of certain highly active chemicals are needed to produce catastrophic cracking, often leading to devastating failure. The stresses can be the result of the crevice loads due to stress concentration, or can be caused by the type of assembly or residual stresses from fabrication (eg. cold working); the residual stresses can be relieved by annealing.

Stress Corrosion or SCC
Intergranular corrosion facilitated by high residual surface stress imposed in the work piece by grinding, machining, or other metal removal or forming process.

Stress-Intensity Factor
A scaling factor, usually denoted by the symbol K, used in linear elastic fracture mechanics to describe the intensification of applied stress at the tip of a crack of known size and shape.

Stretch Flanging
A bending operation; but the line of bending is not straight, rather, it is a concave curvature.

Stretch Forming
The process of forming by applying primarily tensile forces to stretch the sheet metal over a tool or form block.

Stretcher Strains
Elongated markings that appear on the surfaces of some materials when deformed just past the yield point.

Striation
A fatigue fracture feature, often observed in electron micrographs, that indicates the position of the crack front after each succeeding cycle of stress.

Sulfated Ash
Ash content determination by ASTM D874, in which the oil is burned and treated with sulfuric acid. Indicates level of metallic additives in the oil.

Sulfidation
The reaction of a metal or alloy with a sulfur-containing species to produce a sulfur compound that forms on or beneath the surface on the metal or alloy.

Sulfochlorinated Oil
A straight oil containing both chlorine and sulfur where the chlorine (Cl) and sulfur (S) have been attached (bound) directly to the carbon atoms replacing hydrogen (H) atoms.

Sulfonate
A hydrocarbon in which a hydrogen atom has been replaced with the highly polar group, where X is a metallic ion or alkyl radical.

Sulfur
A nonmetalic element frequently used in the formulation of metalworking fluids and an EP additive but is often found as a trace element in oils and other organic compounds.

Superabrasive
Extremely hard abrasives like diamond and cubic boron nitride (cBN) as apposed to conventional and somewhat softer abrasives like aluminum oxide or silicon carbide.

Superabrasive Tools
Abrasive tools made from diamond or cubic boron nitride, the hardest materials known.

Superalloys
Tough, hard-to-machine alloys.

Superplasticity
The ability of certain metals to undergo unusually large amounts of plastic deformation before local necking occurs.

Surface Conditioning Abrasive
Products made with nonwoven abrasives. Formed into cleaning, unitized, or convolute wheels, surface conditioning abrasives can be made with various hardness and grit densities.

Surface Finish
A measurment of how smooth or rough the suface of a part is. There are a wide variety of different measuring systems that look at specific characteristics.

Surface Grinding
A process and machine tool to grind flat and/or square surfaces.

Surface Integrity
A catch-all term for determining how much or how little the material being machined or ground (worked) is changed.

Surface Tension
The tendency of a fluid to want to hang together. It is also a way of measuring how well and quickly a product will spread or flatten out.

Surfactant or Surface Active Agent
Materials capable of lowering the surface and interfacial tension of liquids usually water.

Synthetic Fluid
A metalworking fluid concentrate that does not contain any or very low levels of mineral oil. They are some times called chemical coolants. This class of fluids contains three subclasses true solutions, surface active synthetics (those with a working soluton with a surface tension of less than 45 dynes) and neo-synthetics (fluids with relatively low static surface tension that are built with other than conventional surfactant chemistry).

Synthetic Lubricant
A lubricating fluid made by chemically reacting materials of a specific chemical composition to produce a compound with planned and predictable properties. The resulting base stock may be supplemented with additives to improve specific properties.

T-Slot
Milling cutter for machining T-slots. Desired T-slot shape is reverse of the cutter shape.

Tackifier
A high molecular weighted, fluid polymer added to greases to improve adhesiveness.

Tailstock Drill and Tapholder
An accessory that mounts in a turning machine's tailstock for center-drilling chucked work and tapping.

TAN
(Total) acid number

Tang
Extended flat portion of tapered drill shank, endmill, or other tool that allows maxium power transmission and proper positioning of the tool. Reverse shape of the machine-spindle slot it fits into.

Tap
Cylindrical tool that cuts internal threads and has flutes to remove chips and carry tapping fluid to the point of cut.

Taper Reamer
Reamer designed to produce a reamed hole with a specified taper.

Taper-Turning Attachment
Guide to which a cross slide is attached that permits the turning of tapers without disturbing the alignment of the tailstock. Also permits taper boring.

Tapping
Machining operation in which a tap, with teeth on its periphery, cuts internal threads in a pre-drilled hole having a smaller diameter than the tap diameter.

Tapping Attachment
Fits in a drill-press spindle and automatically reverses the tap when the thread is completed, ensuring proper retraction of the tool.

TBN
(Total) base number.

Tensile Stress / Compressive Stress
Tensile stress is a force that stretches a material. Compressive stress is a force that “squeezes” a material.

Theoretical Density / % theoretical density
The density of a PM part if it was 100% material being pressed. This is a way of expressing how much open space is present in the finished sintered work piece. It will be expressed as percent theoretical density which is the actual density divided by the theoretical density. Very often PM parts are deliberately made with less than 100% theoretical density to leave room for lubricant flow etc.

Theoretical Density or % Theoretical Density
A measure of what percent of the PM part is a void.

Thermal Stability
The ability to resist chemical degradation at high temperature.

Thixotropy
The tendency of grease or other material to soften or flow when subjected to shearing action.

Thread Chaser
Die-type external threading tool. Makes final threading pass.

Thread Grinder
Typically a form grinder as well as thread grinder, this machine differs from other grinders in that precision gears and leadscrews ensure a precise traverse to impart the correct lead to a thread.

Threading
A process of both external and internal (tapping) cutting, turning, and rolling of threads into particular material.

Threading Machine
Typically takes the form of multi-spindle, universal threading machines that use dieheads and thread chasers to cut threads, often automatically or semiautomatically.

Time Change Parts
Parts that are changed based on some predetermined amount of time or cycles: e.g., the tiers are changed after every 100 landings.

Titanium Carbide
Extremely hard material added to tungsten carbide to reduce cratering and built-up edge. Also used as a tool coating.

Toolchanger
Carriage or drum attached to a machining center that holds tools until needed. When needed, the toolchanger inserts the tool into the machine spindle.

Toolholder
Secures a cutting tool during a machining operation.

Toolroom Lathe
High-precision lathe built to hold tighter tolerances than regular, general-purpose lathes.

Tooth Rest
Finger of metal that contacts a cutter edge during resharpening on a tool-and-cutter grinder, ensuring accurate location of edges so they are properly ground.

TOP-Technical Office Protocol
Standardized computer communications for the office; combines with manufacturing automation protocol to permit office/plant computer integration of multi-vendor systems and software.

Total Alkalinity
A measure of a fluids ability to maintain its pH above the point that the selected indicator changes color. It is also used to indirectly measure the concentration of chemical and semichemical fluids by titration.

Toughness
A measure of the ability of a material to resist shock. It is a function of both strength and ductility of the material.

Tracer Attachment
Used to duplicate a workpiece. A stylus connected to a servo traces a template or sample workpiece.

Tramp Oil
A generic term for oil that unintentionally gets into a metalworking fluid. Oil that is "hitching a free ride" typically way, hyrdraulic and spindle oil but can include oil from other sources as well.

Trepanning
Drilling deep holes that are too large to be drilled by high-pressure coolant drills or gundrills.

Tribology
The science of the interactions between surfaces moving relative to each other.

Truing
Changing the shape and/or condition of a grinding wheel so that it runs concentrically with the spindle and is in balance.

Turbine Oil
A top-quality rust-and-oxidation-inhibited (R&O) oil that meets the rigid requirements traditionally imposed on steam-turbine lubrication.

Turning
A workpiece is held in a chuck, mounted on a face plate, or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face.

Turning Machine
Any machine which rotates the workpiece while feeding a cutting tool into it.

Turret Ram Mill
Differs from engine lathe in that the normal compound rest is replaced by pivoting, multi-tool turrets mounted on the cross slide and tailstock.

Twist Drill
The most common type of drill, having one or more cutting edges, and having helical grooves adjacent thereto for the passage of chips and for admitting coolant to the cutting edges.

Undercut
In numerical control applications, a cut shorter than the programmed cut resulting after a command change in direction.

Undershoot
Tendency of a numerical-control/computer-numerical control machine to round off the corners of a programmed path because of servo lag, backlash, or because mechanical systems cannot react quickly to programmed instructions, especially when machine is cold.

Universal Head
Facilitates setups on a tool and cutter grinder by allowing the grinding head to rotate away from the work area, leaving table alignment undisturbed. Also called a swivel attachment.

Universal Milling Attachment
Mounts on a horizontal mill, permitting the spindle to be set at almost any angle.

Universal Milling Machine
A horizontal mill equipped with a table that swivels, with respect to the saddle, allowing angular surfaces to be cut without changing the workpiece's position.

Universal Spiral-Milling Attachment
On a universal mill, permits milling helixes with a helix angle greater than 45 degrees. A milling machine mounted to a plain equipped with a dividing head, it permits the mill to handle work that otherwise would require a universal mill.

Useful Alkalinity
A measure of a fluids ability to maintain its pH above 7.5.

V-Block
Workholding device with V-shaped slot for holding pipe and other round stock during machining or inspection.

V.O.C.
Volatile organic compounds - organic compounds that might evaporate when used and contribute to airborn pollution.

Vacuum Bag Molding
A process for molding reinforced plastics in which a sheet of flexible, transparent material is placed over the lay-up on the mold and sealed.

Vacuum Metalizing
A process in which surfaces are thinly coated with metal by exposing them to the vapor of metal that has been evaporated under vacuum.

Vacuum Refining
Melting and/or casting in a vacuum to remove gaseous contaminants from a metal.

Varnish
A hard coating formed from oil oxidation products that bakes on to surfaces during high-temperature operation of automotive engines and industrial machinery.

Vertical Milling Attachment
Permits a horizontal mill to perform vertical and angled milling.

Viscosity
A expression of how resistant to flow a material is. It is expressed in the time it takes a measured amount to pour though a standard hole at a standard temperature and pressure.

Viscosity Index (VI)
An empirical, unitless number indicating the effect of temperature on the kinematic viscosity of an oil.

Viscosity Index Improver
A polymeric additive designed to increase the viscosity index of an oil. Also known as viscosity modifier.

Viscosity-Temperature Relationship
The manner in which the viscosity of a given fluid varies inversely with temperature.

Vise
Workholding device that mounts on various machining tables.

Volatility
Expressioin of evaporation tendency. The more volatile a petroleum liquid, the lower its boiling point and the greater its flammability.

Way
Longitudinal surface that guides the reciprocal movement of a machine part.

Way Lubricant
Lubricant for the sliding ways of machine tools. A good way lubricant is formulated with special frictional characteristics designed to overcome the stick-slip motion associated with slow-moving machine parts.

Web
On a rotary tool, the portion of the tool body that joins the lands. Web is thicker at the shank end, relative to the point end, providing maximum torsional strength.

Weld Point
The lowest applied load in kilograms at which the rotating ball in the Four Ball EP test either seizes and welds to the three stationary balls, or at which extreme scoring of the three balls results.

Wettability
The relative ease with which a liquid spread over a surface. Often express as dynamic and/or static surface tension.

Wetting Agent
An additive or chemical that reduces the surface and interfacial tension to facilitate the spreading of the liquid over the surface.

Wheel Flange
Metal plate inside the griding-wheel hole that allows the wheel to be mounted on a spindle.

Wheel-Balancing Stand
Used to ensure that a grinding wheel is balanced before mounting it on the machine.

Woodruff Cutter
Milling cutter used for cutting keyways.

Work Hardening or Cold Worked
Work hardening, strain hardening, or cold work is the strengthening of a material due to plastic deformation. In metallic solids permanent change of shape is usually carried out on a microscopic scale by defects called dislocations which are created by stress and rearrange the material by moving through it. At normal temperatures these defects do not anneal out of the material but build up as the material is worked, interfering with one another's motion and thus increasing strength and decreasing ductility. Any material with a reasonably high melting point can be strengthened in this fashion. Alloys not amenable to heat treatment, including low-carbon steel, are often work-hardened. Some materials cannot be work-hardened at normal ambient temperatures; for example indium, which has a low melting point. This makes indium suitable for manufacturing gaskets, which deform to fill gaps, for high-vacuum use. Work hardening is often produced by the same process that shapes the metal into its final form, including cold rolling (contrast hot rolling) and cold drawing. Techniques have been designed to maintain the general shape of the work piece during work hardening, including shot peening and constant channel angular pressing. A material's work harden ability can be predicted by analyzing a stress-strain curve, or studied in context by performing hardness tests before and after a process.

Work Piece
The material that is being machined or ground. The material that is being worked.

Work-Squaring Bar
Mounts to the table of a contour band machine and automatically squares the work to the blade.

Working pH
The pH of a used coolant working solution after it has “settled down” for a period of time.

Wrought
To mechanically work a material as apposed to cast the material. Typically material that has been rolled, drawn or extruded as apposed to cast. Wrought iron is so named because it is worked from a "bloom" of porous iron mixed with slag and other impurities. The word "wrought" is an archaic past tense of the verb to work. As irregular past-tense forms in English have historically been phased out over long periods of time, wrought became worked. Wrought iron literally means worked iron.

ZDTP or ZDP
Widely used as an anti-wear-additive in engine oils to protect heavily loaded parts, particularly the valve train mechanisms from excessive wear.

Zirconia
An oxide of zirconium that has use as an abrasive.