M B Grade - A term applied to Open-Hearth steel wire in the .45/.75 carbon range either hard drawn or oil tempered. Oil tempered wire of M B and W M B types are the most widely used of all spring wires. Oil tempered wire is more suitable to precision forming and casting operations than hard drawn wire, because of close control of tensile strength and superior straightness. . NOTE M B, H B and extra H B designate Basic Open Hearth steels, while W M B, W H B and extra W H B designate Acid Open Hearth Steels. The chemical composition and the mechanical properties are the same for both basic and acid steel.

M sections (Bantam BeamsTM , Junior BeamsTM) - Light footweight beams primarily used in the construction of pre-engineered housing. These beams are produced in lighter footweights, usually six to 10 pounds per foot, than traditional structural products.

Machinability Index - A relative measure of the machinability of an engineering material under specified standard conditions.

Machine Allowance - Stock added to the part to permit machining of the part to final dimensions.

Machine Drawing - An engineering drawing which depicts the final size and shape of the part for its end use.

Machine Lock Forming - See Lockseam.

Machine Tool - A power-driven machine designed to bore,cut,drill or grind metal or other materials

Machining, Finish - Machining a surface to give it the desired finish.

Machining, Rough (Rough Finishing) - Removing excess stock (material) with a machine tool thus shaping it in preparation for finish maching.

Machinist - A person who is skilled in the operation of machine tools. He must be able to plan his own procedure and have knowledge of heat-treating principles.

Macroetch - A testing procedure for conditions such as porosity, inclusions, segregations, caburization, and flow lines from hot working. After applying a suitable etching solution to the polished metal surface, the structure revealed by the action of the reagent can be observed visually.

Magnesium - Chemical symbol Mg. A silvery,moderately hard,strong and light metal. Used in ductile iron production, steel desulfurization and chemical reduction. Growing use as substitute for aluminum and zinc in die casting, due to lightweight and high strength.

Magnetic Coil - An electrical device mounted on the solenoid valves that supply the energy needed to shift the valve.

Magnetic Crack Detection - The baaaaaar or components to be tested is magnetised by passing a heavy current through it or by making it the core of a coil through which a heavy current is passed. Cracks or inclusions cause the magnetic flux to break the surface forming free magnetic poles. When the component is sprayed with a suspension of finely divided magnetic particles they collect at the free poles to visibly show the presence of defects.

Magnetic Chuck - A flat, smooth surfaced work holding device which operates by magnetism to hold ferrous metal workpieces for grinding.

Magnetic Particle Testing - A non-destructive test method of inspecting areas on or near the surface of ferromagnetic materials. The metal is magnetized, then iron powder is applied. The powder adheres to lines of flux leakage, revealing surface and near surface discontinuities. Magnetic particle testing is used both raw material acceptance testing and product inspection. Quality levels are usually agreed on in advance by the producer and purchaser.

Magnetism - Commonly expressed as permeability which is the ratio of the magnetic induction to the magnetic intensity. The important factor to remember is that the permeability increases as the material becomes more magnetic. The 300 series stainless is non-magnetic in the annealed condition.

Main Drives - Large gear transmissions that power the finishing mill's pinion drives.

Main Filter - Filter used to clean the hydraulic oil supplied by the main pumps before the oil goes to the system's cylinders.

Main Heat - Heat cycle setting on the welder for the main part of the weld.

Main Oil Pump - A pump that pumps oil to the bearings and the controls of a blower when the blower is up to speed.

Main Pump - The pumps that produce the hydraulic pressure for the A.G.C. and C.V.C. reducing station.

Main Steam Header Valve - A valve located before the throttle valve on the main steam line coming into the turbine.

Main Trip Valve - Electrically operated valve that stops or allows flow through a line.

Make-Up - Water that is added to accumulator drum to ensure proper water level.

Make-Up Tank - A component of the cooling system that allows additional coolant to be added to the system as needed.

Malleability - The property that determines the ease of deforming a metal when the metal is subjected to rolling or hammering. The more malleable metals can be hammered or rolled into thin sheet more easily than others.

Malleable - Capable of being extended or shaped by hammering or rolling.

Malleable Iron - A cast iron made by prolonged annealing of white iron in which decarburization,graphitization or both take place to eliminate some or all of the cementite. The graphite is in the form of temper carbon. If decarburization is the predominant reaction, the product will exhibit a light fracture surface; hence whiteheart malleable. Otherwise, the fracture surface will be dark;hence blackheart malleable. Only the blackheart malleable is produced in the United States. Ferritic malleable has a predominantly ferritic marix;pearlitic malleable may contain peaaaarlite,spheroidite or tempered marensite, depending on heat treatment an desired hardness.

Mallet - Wooden hammer.

Man-Hours Per Ton - This is a measure of labor efficiency D1the ratio of total hours worked by steel employees to the tons shipped for a given period of time. Changes in the inventory level and work that is contracted out will affect the reported measurement.

Mandrel Forging - The process of rolling and forging a hollow blank over a mandrel in order to produce a weldness, seamless ring or tube.

Manganese - (Chemical symbol Mn.) Element No. 25 of the periodic system; atomic weight 54.93. Lustrous, reddish-white metal of hard brittle and, therfore, non-malleable character. The metal is used in large quantities in the form of Spiegel and Ferromanganese for steel manufacture as well as in manganese and many copper-base alloys. Its principal function is as an alloy in steel making: (1) It is ferrite-strengthening and carbide forming element. It increases hardenability inexpensively, with a tendency toward embrittlement when too high carbon and too high manganese accompany each other. (2) It counteracts brittleness from sulfur.

Manganese Steel (Austenitic) - See Hadfield Manganese Steel

Manual - Describes the status of the operation when the operator has total control.

Maraging - A precipitation-hardening treatment applied to a special group of high-nickel iron-base alloys (maraging steels) to precipitate one or more intermetallic compounds in matrix of essentially carbon-free martensite.

Maraging Steel - A high alloyed steel that is hardened by both martensite transformation and by age hardening.

Mark, Arbor - Surface damage in the vicinity of a coil ID caused by contact with a roughened, damaged or noncircular arbor

Mark, Bearing - A depression in the extruded surface caused by a change in bearing length in the extrusion die

Mark, Bite - A line which is generally perpendicular to the rolling direction

Mark, Bristle - Raised surface about one inch long, crimped wire shaped and oriented in any direction

Mark, Carbon - Gray or black surface Marking caused by contact with carbon runout blocks

Mark, Chatter (Roll or Leveler) - Numerous intermittent lines or grooves that are usually full width and perpendicular to the rolling or extrusion direction

Mark, Edge Follower - Faint intermittent marks at the edge of a cold rolled product which are usually perpendicular to the rolling direction. This mark is caused by action of devices designed to rewind coils without weave.

Mark, Handling - (1)For rolled products, an area of broken surface that is introduced after processing. The mark usually has no relationship to the rolling direction. (2)For extrusions, damage that can be imparted to the surface during handling operations.

Mark, Heat Treat Contact - Brownish, iridescent, irregularly shaped stain with a slight abrasion located somewhere within the boundary of the stain. It is a result of metal-to-metal contact during the quenching of solution heat-treated flat sheet or plate

Mark, Inclusion - Appearance of surface (which may also be creased)near a slit edge, caused by sheet contacting the slitter knife

Mark, Mike - Narrow continuous line near the rolled edge caused by a contacting micrometer

Mark, Roll Bruise - A greatly Enlarged roll mark whose leight or depth is very shallow. See also Mark Roll

Mark, Roll skid - A full width line perpendicular to the rolling direction and repeating as a function of a work roll diameter

Mark, Roll - (1)For rolled products, a small repeating raised or depressed area caused by the opposite condition on a roll diameter. (2) For extrusions, a longitudinal groove or indentation caused by pressure from contour rolls as a profile (shape) passes through them for dimensional correction

Mark, Rub - A large number of very fine scratches or abrasions. A rub mark can occur by metal-to-metal contact, movement in handling and movement in transit

Mark, Snap - A band-like pattern around the full perimeter of an extruded section and perpendicular to its length. A stop mark occurs whenever there is an abrupt change in the extrusion process. See also mark, Stop

Mark, Stop - A band-like pattern around the full perimeter of an extruded section and perpendicular to its length. A stop mark occurs whenever the extrusion process is suspended. See also, Mark, Snap

Mark, Stretcher Jaw - A cross hatched appearance left by jaws at the end(s) of metal that has been stretched. These marks are seen if insufficient metal has been removed after the stretching operation

Mark, Traffic - Abrasion which results from relative movement between contracting metal surfaces during handling and transit. A dark color from the abrasively produced aluminum oxide is usually observed. A mirror image of a traffic mark is observed on the adjacent contacting surface

Mark, Whip - A surface abrasion which is generally diagonal to the rolling direction. It is caused by fluttering action of the metal as it enters the rolling mill

Mark - Damage in the surface of the product whose name is often described by source.

Marking Up - Writing information on coils and blackboard.

Martempering - Quenching an austenitized ferrous alloy in a medium at a temperature in the upper part of the martensite range, or slightly above that range, and holding it in the medium until the temperature throughout the alloy is substantially uniform. The alloy is then allowed to cool in air through the martensite range.

Martempering (Interrupted Quenching) - A hardening treatment of a steel involving a slow cool through the martensitic transformation range to reduce stresses associated with the quenching of austenite. An important aspect of martempering is that no transformation product other than martensite should form.

Martensite - A distinctive neddle like structure existing in steel as a transition stage in the transformation of austenite. It is the hardest constituent of steel of eutectoid composition. It is produced by rapid cooling from quenching temperature and is the chief constituent of hardened carbon tool steels. Martensite is magnetic.

Martensite - "A generic term used for microstructures formed by diffusionless phase transformations. A constituent found in hardened steel; has a needle like microstructure. See also Mf and Ms. "

Martensitic - Small category of stainless steel characterized by the use of heat treatment for hardening and strengthening. Martensitic stainless steels are plain chromium steels with no significant nickel content. They are utilized in equipment for the chemical and oil industries and in surgical instruments. The most popular martensitic stainless steel is type 410 (a grade appropriate for non-severe corrosion environments requiring high strength).

Martensitic Hardening - Martensitic stainless steels can be hardened by heating above the transformation range to temperatures of 1700 to 1950 degrees F., followed by cooling in air or oil. This process provides the maximum toughness.

Martensitic Stainless Steels - A corrosion-resistant ferrous alloy with a predominant martensitic phase. Mass Effect . . . The effect that the mass of a component has on the properties of the material from which the part is made. In castings, such effects may arise due to the effect of mass on the solidification rate and on the rate of temperature change during heat treatment.

Mass Effect - The effect that the mass of a component has on the properties of the material from which the part is made. In castings such effects may arise due to the effect of mass on the solidification and on the rate of temperature change heat treatment.

Master Pattern - The object from which a die can be made; generally a metal model of the part to be cast with process shringage.

Matalloid - (a) Element intermediate in luster and conductivity between the true metals and non-metals. Arsenic, antimony, boron, tellurium, and selenium, etc., are generally considered metalloids; frequently one allotropic modification of an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn. (b) In steel metallurgy, metalloid has a specialized, even if erroneous, meaning; it covers elements commonly present in simple steel; carbon, manganese, phosphorus, silicon and sulfur.

Matchplate - A plate of metal or other materials on which patterns and gating systems, split along the parting line, are mounted back to back to form an integral piece.

Material Safety Data Sheets - (MSDS) Sheets that document safety issues associated with various materials used.

Matt or Matte Finish - (Steel) Not as smooth as normal mill finish. Produce by etched or mechanically roughened finishing rolls.

Matte Finish - A dull or grit surface appearance achieved by rolling on rolls which have been roughened by mechanical, chemical, or electrical means to various degrees of surface texture.

Matte Surface - A dull surface appearance on a tin plate product; non-reflowed tinplate. See Re-flowed Surface.

Max Coil - Largest size coil a customer will take; Tin Mill may have to split a coil to achieve this weight.

Maximum Stress - In testing of the strength of steel a sample is machined into a standard test piece and is stretched In a tensile testing machine until it breaks. The results are expressed in N/mm2 and is the value of the maximum load reached in the test divided by the original cross sectional area of the specimen.

McKay Leveler - A series of four rolls (two top, two bottom) necessary to level or remove coil set in order to feed coil ends through the shear.

McQuaid EHN Grain Size Test - A method of assessing grain size. It consists of a test piece at 927oC for 8 hours by slow cooling anmd subsequent microscopical examination. The grain size is measured at x100 magnification and compared to standard chars, the figures range from No.1-very coarse to No. 8-very fine.

Meallographic Structure - The nature, distribution, and amounts of the metallographic constituents in a metal.

Mean Diameter - The average of two measurements of the diameter at right angles to each other

Measuring Table - A precise measuring device.

Mechanical Level Indicator - Device that uses a float to measure the level of oil in a tank.

Mechanical Properties - Properties of a material that reveal its strength and elastic behavior.

Mechanical Properties - Those properties of a material that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength, and fatigue limit. These properties have often been designated as "physical properties," but the term "mechanical properties" is much to be preferred.

Mechanical Tubing - Steel tubing products used in the manufacture of hydraulic cylinders, in mechanical parts for autos and trucks, construction and farm equipment and in furniture,bicycles and many other applications.

Mechanical Working - Plastic deformation or other physical change to which metal is subjected, by rolling, hammering, drawing., etc. to change its shape, properties or structure.

Medium-Carbon Steel - Contains from 0.30% to 0.60% carbon and less than 1.00% manganese. May be made by any of the standard processes. See Low-Carbon Steel and High-Carbon Steel

Meehanite - A trade name applied to a certain type of cast iron.

Merchant Bar - A group of commodity steel shapes that consist of rounds, squares, flats, strips, angles, and channels, which fabricators, steel service centers and manufacturers cut, bend and shape into products. Merchant products require more specialized processing than reinforcing bar.

Mesh - To engage, as the teeth between two gears.

Metal - An opaque, lustrous, elemental substance that is a good conductor of heat and electricity and, when polished, a good reflector or light. Most metals are malleable and ductile and are, in general, denser than other substances.

Metal Spraying - A process for applying a coating of metal to an object. The metal, usually in the form of wire, is melted by an oxyhydrogen or oxyacetylene blast or by an electric arc and is proficted at high speed by gas pressure against the object being coated.

Metalloid - 1) An element intermediate between metals and nonmetals possessing both metallic and nonmetallic properties, as arsenic, 2) sometimes applied to elements commonly bonded in small amounts in steel, as carbon, manganese, boron, silicon, sulfur, and phosphorus.

Metallstatic Pressure - A compound phase referring to hydrostatic pressure, substituting Metall since Hydro connotes water.

Metallurgical Bond - The bond between two metals whose interface is free of voids, oxide films, or discontinuities.

Metallurgy - The science and technology of metals, a broad field that includes but is not limited to the study of internal structures and properties of metals and the effects on them of various processing methods.

Metalock - A method of cold repair of castings and forgings.

Metals Comparator - An instrument for testing or identifying metallic and nonmetallic parts. Parts are placed in an electromagnetic field and a standard parts in a matched electromagnetic field. Distortions of the magnetic fields are compared on an oscilloscope.

Metamic - A metal ceramic high in Cr-Al2O3.

Metastable (Unstable) - A state of pseudo-equilibrium.

Mexico Bay Sand - A sand similar to Michigan City dune sand mined at Selkirk Beach, near Mexico NY., on Lake Ontario. It has a silica content of 90% and over.

Meyer Hardness Test - A test to determine tendency of a metal to harden when deformed plastically. A series of indentations are made in the metal using a fixed-diameter ball and progressively increasing loads.

Mf - The temperature at which martensite formation finishes during cooling.

Mg - Chemical symbol for Magnesium

Mic; Mike - A term used for micrometer or to messure with a micrometer.

Mica Schist - A type of micaceous refractory rock used for lining cupolas and other melting furnaces.

Mica Strainer - A skim core made of thin mineral silicates crystallizing in monoclinic form.

Michigan Sand - Core sands of dune or lake sand and bank sands found in Michigan.

Micrometer, depth - A micrometer in which the spindle projects through a flat accurately machined bar. Used to measure the depth of holes or recesses.

Micrometer, thread - A micrometer in which the spindle is ground to a point having a conical angel of 60 degrees. The anvil,instead of being flat, has a 60 degree v-shaped groove which fits the thread.

Micro Pipes (Brit.) (Microshrinkage) - Tiny cavities, a fraction of a millimeter in diameter, with irregular outlines, which occur in castings. Etching shows they occur at intersections of convergent dendritic directions.

Micro-Tester - A low load hardness tester, suitable for both Vickers and Knoop tests, working with loads of between 10 to 3000 grams.

Microbands (deformation) - Thin sheet like volumes of constant thickness in which cooperative slip occurs on a fone scale. They are an instability which carry exclusively the deformation at medium strains when normal homogeneous slip is precluded. The sheets are aligned at +/- 55(degrees) to the compression direction and are confined to individual grains, which usually contain two sets of bands. Compare shear bands.

Microcast Process - A patented method of precision-casting alloys, as Vitallium, Monel, Inconel and the Haynes Stelite alloys.

Microetching - Etching of metal samples for examination under the microscope.

Microformer - A type of extensometer for measuring elongation of test piece in a tensile test.

Microhardness - The hardness of microconstituents of a material.

Microinch - 0.000001 (1/1,000,000th) of an inch. A common unit of measurement in surface measurement research and in standard roughness (surface) unit values of performance of machinery.

Microlug - A test coupon used to give rapid indication of the effectiveness of magnesium treatment of ductile iron.

Micrometer - A device used to measure gauge.

Micron - A unit of length equal to one millionth of metre (0.001mm).

Microporosity - See Microshrinkage

Microradiography - The process of passing x-rays through a thin section of an alloy in contact with a photographic emulsion, and then magnifying the radiograph 50 to 100 times to observe the distribution of alloying constituents and voids.

Microscopic - Minute object or structures which are invisible or not clearly distinguished without the use of a microscope.

Microsection - A metal specimen whose surface has been polished and etched to reveal the microstructure.

Microshrinkage - Very finely divided porosity resulting from interdendritic shrinkage resolved only by use of the microscope; may be visible on radiographic films as mottling. Etching shows they occur at intersections of convergent dendritic directions.

Microspectroscopy - A method of identifying metallic constituents using spectrographic arc.

Microtone (Brit.) - An instrument for cutting thin sections of soft specimens.

Microvalve - A control valve used to control the hydraulic pressure to the clutch plates on the winch drive.

Mid-Weld - Two or more joints welded to form a longer one

Migra Iron (Brit.) - A special pig iron for high quality castings.

Mike Mark - Narrow continuous line near the rolled edge caused by a contacting micometer

Mikro-Tester - A low load hardness tester, suitable for both Vickers and Knoop tests, working with loads of between 10 to 3000 grams.

MIL STD - United States Government military standards, specifications, usually requiring rugged, exacting testing equal to the exigencies of combat usage.

MnChemical symbol for Manganese. -

Mill - A milling machine. Also, the act of performing an operation on the milling machine.

Mill Edge - A hot band processed through the Pickler without being side trimmed. This replaces the old term, band edge.

Mill Finish - A surface finish produced on sheet and plate. Characteristic of the ground finish used on the rolls in fabrication.

Mill Scale - Iron oxide scale formed on steel during hot working processes, cooled in air

Mill Stars - Multi-pointed white iron or hard iron bodies used in a Tumbling Barrel to assist in polishing and cleaning.

Milling - Removing metal with a milling cutter.

Milling Cuffer - A cutting tool, generallt cylindridcal in shape. Used on a milling machine and operated essentially like a circular saw.

Milliroentgen (mr) - A sub-multiple of the roentgen equal to one-thousandth (1/1000th) of a roentgen.

Milliscope (Brit.) - An instrument which gives an electrical warning when melt reaches a predetermined temperature.

Mineral - Natural inorganic substance which is either definite in chemical composition and physical characteristics or any chemical element or compound occurring naturally as a product of inorganic processes.

Mini-Mills - Normally defined as steel mills that melt scrap metal to produce commodity products. Although the mini-mills are subject to the same steel processing requirements after the caster as the integrated steel companies, they differ greatly in regard to their minimum efficient size, labor relations, product markets, and management style.

Minimill Steel Producer - A steel company, which manufactures solid, steel products; starts with the steelmaking operation, generally consisting of an electric arc furnace, and converts the liquid steel into solid products. See Integrated Steel Producer.

Minimized Spangle - A dull Hot-Dipped Galvanized surface appearance in which the normal zinc formation has been suppressed; achieved by applying water droplets or some other nucleating agent to the zinc surface after the bath but before the zinc solidifies to suppress the growth of spangle.

Minimum Residual Stress (MRS) - The term applied to products, usually flat rolled, which have been processed to minimize internal stress of the kind that causes distortion when material is disproportionately removed from on of the two surfaces through mechanical or chemical means.

Minimum Triple Spot Average Coating - The average of three coating weights test results obtained from a full width sample of a galvanized (or any other coated) coil 2 inches from each end and dead center.

Minor Diameter - The smallest diameter of a screw thread. Also known as the Root diameter.

Mirror Finish - A highly reflective finish obtained by polishing with successively finer abrasive and buffing extensively free of grit lines. Finish is used most for architectural applications. A comparable finish produced by cold-rolling is Ulbrichs UlbraBright, which currently is not being produced.

Mischmetal - An alloy of rare earth metals containing about 50% lanthanum, neodymium, and similar elements.

Miscibility - Solubility; ability of two or more liquids to form a homogeneous solution.

Mismatch - Error in register between two halves of a forging by opposing die halves not being in perfect alignment

Misrun - Denotes an irregularity of the casting surface caused by incomplete filling of the mold due to low pouring temperature, gas back-pressure from inadequate venting of the mod, and inadequate gating.

Misting - A coating defect consisting of a condition encountered, primarily on D & I high speed beverage can coating machines, which appears as many fine spots of coating.

Mitis Casting - Casting of very mold steel.

Mixed Gas - A natural gas and air mixture which lowers the BTU value of the gas to approximately 750 BTU per cubic feet.

MnChemical symbol for Manganese. - NULL

Mo - Chemical symbol for Molydenum

Mock-Up - A full-size model built accurately for study, testing or display.

Model - A proportional representation of an object in any scale.

Modell Number - A value giving a measure of wear resistance.

Modification - A process in which the eutectic temperature, structure, and composition of aluminum-silicon alloys are apparently altered by the addition of small amounts of a third element, such as sodium. A similar phenomenon can be effected by chill casting.

Modules of Elasticity - The ratio of stress to corresponding strain throughout the range where they are proportional. As there are three kinds of stresses, so there are three kinds of moduli of elasticity for any material-modulus in tension, in compression, and in shear.

Modulus of Elasticity - The number which represents the relative "springness" of a given type of metal. All steels have the same modulus of elasticity or "springiness" regardless of the tensile or yield strengths. That is, until the yield point is reached they all stretch the same amount for a given load. Aluminum, on the other hand, is more elastic than steel and thus will stretch more than steel under the same loading.

Modulus of Elasticity (tension) - Force which would be required to stretch a substance to double its normal length, on the assumption that it would remain perfectly elastic, i.e., obey Hooke's Law throughout the twist. The ratio of stress to strain within the perfectly elastic range.

Modulus of Resilience (ur) - The amount of strain energy per unit volume required to stress a material from zero to the yield stress limit. The modulus of resilience is proportional to the area under the elastic portion of the stress-strain diagram. Units are Pa or psi.

Modulus of Rigidity - "In a torsion test the ratio of the unit shear stress to the displacement caused by it per unit length in the elastic range. See Shear Modulus "

Modulus of Rupture - Used in both bending and torsion testing. In bending, the modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus.

Modulus of Toughness (ut) - Amount of work per unit volume of a material required to carry that material to failure under static loading. Equal to the area under the entire stress-strain curve. Units are Pa or psi.

Mogullizer - Equipment for sealing by vacuum impregnation of small pores in castings.

Moh's Scale - A scratch hardness test for determining comparative harness using ten standard minerals, from talc to diamond.

Moisture Content - The amount of water contained in a substance that can be driven off by heating at 220 - 230 B0F (104.4 - 110 B0C).

Moisture Teller - A patented apparatus for the rapid determination of moisture content of molding sand.

Molasses Water - A solution of water and molasses sprayed on sand molds to strengthen mold surface and yield a fine finish layer.

Mold Blower - Molding equipment for blowing sand mixture onto the pattern with compressed air; allows for faster production than gravity rollover dump.

Mold Board (Follow Board) - The board upon which the pattern is placed to make the mold.

Mold Cavity - The space in a mold which is filled with liquid metal to form the casting upon solidification. The channels through which liquid metal enters the mold cavity (sprue, runner, gates) and reservoirs for liquid metal (risers) are not considered part of the mold cavity proper.

Mold Clamp - Devices used to hold or lock cape and drag flask parts together.

Mold Coating (Mold Facing, Dressing) - 1) Coating to prevent surface defects on permanent mold castings and die castings, 2) coating on sand molds to prevent metal penetration and improve metal finish.

Mold Cover Half (Cover Die) - 1) The top half of the mold, the cope, 2) in die casting, the front half of the die, which remains stationary as the die is opened.

Mold Facing - See Mold Coating

Mold Jacket - A wooden or metal form slipped over a mold to support the side during pouring.

Mold Shift - A casting discontinuity resulting from misalignment of the cope and drag halves.

Mold Wash - A slurry of refractory material,such as graphite and silica flour,used in coating the surface of the mold cabity to provide an improved casting surface.

Mold Weight - A weight that is applied to the top of a mold to keep the mold from separating.

Moldability - Ability of sand to flow into a flask and around a pattern; measured in the amount of sand falling through an inclined screen or slot.

Moldabilty Controller - A patented device for controlling water additions to sand mix to maintain a consistent moldability index.

Molding Gravel - The coarser and more permeable grades of molding sand generally used in production casting of exceptional size and weight.

Molding Machine - A machine for making molds.

Molding Material - A material suitable for making molds into which molten metal can be cast.

Molding Sand Mixture - A sand mixture suitable for making molds into which molten metal can be cast.

Molding Sands - "Sands containing over 5% natural clay, usually between 8 and 20%. See also Naturally Bonded Molding Sand "

Molding, Bench - Making sand molds by hand tamping loose or production patterns at a bench without assistance of air or hydraulic action.

Molding, Floor - Making sand molds from loose or production patterns of such size that they cannot be satisfactorily handled on a bench or molding machine, the equipment being located on the floor during the entire operation of making the mold.

Molding, Pit - Molding method in which the drag is made in a pit or hole in the floor.

Molecular Weight - Weight of the smallest quantity of a substance processing all its normal physical properties.

Molecule - The smallest particle of a substance that can exist in the free state and which has the same composition as any larger mass of the substance.

Molybdenum - (Chemical symbol Mo) Element No. 42 of the peridic system; atomic weight 95.95. Hard, tough metal of grayish-white color, becoming very ductile and malleable when properly treated at high temperatures; melting point 4748 (degrees) F.; boiling point about 6600 (degrees) F.; specific gravity 10.2 . Pure molybdenum can best be obtained as a black powder, by reduction of molybdenum trioxide or ammonium molybdate with hydrogen. From this powder, ductile sheet and wire are made by powder metallurgy techniques; these are used in radio and related work. Its principal functions as an alloy in steel making: (1) Raises grain-coarsening temperature of austenite. (2) Deepens hardening. (3) Counteracts tendency toward temperbrittleness. (4) Raises hot and creep strength, red hardness. (5) Enhances corrosion resistance in stainless steel. (6) Forms abrasion-resisting particles.

Molybdenum (Mo) - An alloying element used as a raw material for some classes of stainless steel. Molybdenum in the presence of chromium enhances the corrosion resistance of stainless steel.

Molybdic Oxide - The oxide of molybdenum; added to the furnace in briquetted form as an important finishing constituent in nitriding steels.

Monel - A high nickel alloy, approximately 67% Ni, 28% Cu, the balance Fe, Mn, Si and other elements. Monel metal is resistant to corrosion and is widely used to resist the action of acids.

Monitoring - 1) Periodic or continuous determination of the does rate in an occupied area (area monitoring) or the does received by a person (personnel monitoring), 2) periodic or continuous determination of the amount of ionizing radiation or radioactive contamination present in an occupied region, as a safety measure for purposes of health protection, 3) personnel - monitoring any part of any individual, his breath, or excretions, or any part of his clothing.

Monitoring Area - Routine monitoring of the level of radiation or of radioactive contamination of any particular area, building, room or equipment. Usage in some laboratories or operation distinguishes between routine monitoring and survey activities.

Monkey Cooler (Brit.) - In a blast furnace, the smaller of a series of three water coolers protecting the cinder notch. The largest is the cooler, while the in-between cooler is the intermediate cooler.

Monocast Process - A patented application of resin-bonded sand to line the flask in the production of centrifugal cast pipe. The resin-bonded layer is thinner than the conventional sand lining.

Monotectic - "An isothermal reversible reaction in a binary system, in which a liquid on cooling, decomposes into a solid and a second liquid of different composition. (Compare with Eutectic.) "

Monotron - An instrument for measuring indentation hardness. It is fitted with two dials, one to measure depth of penetration, the other the load.

Months of Inventory - Ratio of the end-of-period inventory to average monthly level of sales for the period.

Montmorillonite - A very plastic clay, more siliceous than kaolinite; the principal constituent of bentonite.

Moore, R. R., Fatigue Machine - A constant load rotating bending type fatigue testing machine.

Morgoil - Oil used to lubricate the finishing mill back-up roll bearings.

Morgoil Alarm - A warning received when morgoil pressure is low or morgoil flow is stopped.

Morgoil Pumps - Pumps that produce the morgoil pressure for the morgoil system.

Morgoil System - System that encompasses all the parts needed to supply morgoil to the back-up rolls.

Morse Taper - A self-holding standard taper largely used on small cutting tools such as deills,end mills ,reamers and, on some machines, spindles in which these tools are used.

Mosture, Workable - That range of moisture content within which sand fills, rams, draws, and dries to a satisfactory mold, and within which the sand does not dry out too fast to mold and patch.

Mother Metal - The molten alloy just before final solidification and freezing out of the solid.

Motorized Variac - An autotransformer for stepless voltage control in shell molding.

Mottled Cast Iron - Iron which consists of a mixture of variable proportions of gray iron and white cast iron; such a material has a mottled fracture.

Mottling - A coating defect consisting of a non-uniform appearance of the cured coating in which the coating has a random, discontinuous poor flow or partial dewetted appearance.

Mottling, pressure - Non-uniform surface appearance resulting from uneven pressure distribution between adjacent layers of the product.

Movers/Haulers - Equipment used to transport in process inventory at WSX. These include cranes, forklift trucks, flatbed trucks, railroad cars, transfer cars, conveyor systems, and slab haulers.

MP - Melting point.

Ms - The temperature at which transformation of austenite to martensite starts during cooling.

Mud - "A term frequently used to designate plastic lining materials. See also Daubing "

Mud Daub - See Daubing

Mud Drum - The lower drum of a boiler. It is used as a settling point for solids contained in the feedwater and as a feedpoint for the lower wall headers and floor tubes.

Muffle Furnace (Kiln) - A furnace in which the heating is indirect; the material to be heated is contained in a refractory container heated from the outside.

Mufflers - A device that quiets the steam exhausted from the boiler before it exits to the atmosphere.

Muliductor Power Source - A device to convert standard 3-phase, 60 cycle current to single- phase, 180-cycle current, so-called medium frequency; produces a strong, controlled stirring action for induction melting.

Mullen Test - Measurment of bursting strength of foil in pounds per square inch. Testing machine applies increasing pressure to one square inch of the sample until it ruptures.

Muller - A type of foundry sand-mixing machine.

Mulling and Tempering - The thorough mixing of sand with a binder, either natural or added, with lubricant of other fluid, as water.

Mult - A "mult" is the term used to describe the slitting of a coil into multiple smaller strips. If a coil is slit into strips less than 9", each strip is referred to as a "mult" and does not receive an individual IPM number. Mults are not removed from the line individually, but as a whole coil unit. For reasons pertaining to customer orders, however, they may be separated and packaged with "mults" from other coils for shipping.

Multi stage pumps - No. 3 and No. 10 pumps that are designed to put out different amounts of water pressure by changing the speed of the pump by opening up different ports on the turbine of the pump.

Multiple Mold - A composite mold made up of stacked sections, each of which produces a complete gate of castings, and poured from a central downgate.

Multiple-Thread-Screw - A screw made of two or more threads to provide an increased lead with specified pitch.

Muntz Metal (A refractory Alloy) - Alpha-beta brass, 60% copper and 40% zinc. Stronger than alpha-brass and used for castings and hot-worked (rolled, stamped, or extruded) products. High strength brasses are developed from this by adding other elements.

Mushet Steel - An air hardened steel containing about 2% c, 2% Mn, and 7% W, developed by Scotsman Robert Musket in 1870.

Mushy Stage - The state between sold and liquid in alloys which freeze over a wide range of temperatures.

Music Wire - A polished high tensile strength cold drawn wire with higher tensile strength and higher torsional strength than any other material available. These high mechanical properties are obtained by a combination of the high carbon content, the patenting treatment and by many continuous passes through drawing dies. The high toughness characteristic of this material is obtained by the patenting. Such wire is purchased according to tensile strength, not hardness.

Machinability - The relative ease of machining a metal.

Machinability - The capacity of a material to be machined easily.

Macro-Etch - Etching of a metal surface for accentuation of gross structural details and defects for observation by the unaided eye or at magnifications not exceeding ten diameters.

Macroetch Test - Consists of immersing a carefully prepared section of the steel in hot acid and of examining the etched surface to evaluate the soundness and homogeneity of the product being tested.

Macroetching - Etching of a metal surface with the abjective of accentuating gross structural details, for observation by the unaided eye or at magnifications not exceeding ten diameters.

Macrograph - A graphic reproduction of a prepared surface of a specimen at a magnification not exceeding ten diameters. When photographed, the reproduction is known as a photomacrograph (not a macrophotograph).

Macrograph - A photographic reproduction of any object that has not been magnified more than ten times.

Macroscopic - Visible either with the naked eye or under low magnification (as great as about ten diameters.

Macrostructure - The structure of a metal as revealed by examination of the etched surface at a magnification not exceeding ten diameters.

Macrostructure - The structure of metal as revealed by macroscopic examination.

Macrostructure - The structure of metals as revealed by examination of the etched surface of a polished specimen at a magnification not exceeding ten diameters.

Magnetic-Particle Inspection - A nondestructive method of inspection for determining the existence and extent of possible defects in ferromagnetic materials. Finely divided magnetic particles, applied to the magnetized part, anre attracted to and outline the pattern of any magnetic-leakage fields created by discontinuities.

Magnetite - The oxide or iron of intermediate valence which has a composition close to the stoichiometric composition Fe3O4.

Malleabilizing - A process of annealing white cast iron in such a way that the combined carbon is wholly or partly transformed to graphitic or free carbon or, in someinstances, part of the carbon is removed completely.

Manual Welding - Welding where in the entire welding operation is performed and controlled by hand.

Martempering - (1) A hardening procedure in which an austenitized ferrous material is quenched into an appropriate medium at a temperature just above the Ms temperature of the material, held in the medium until the temperature is uniform through-out -but not long enough for bainite to form - and then cooled in air. The treatment is frequently followed by tempering. (2) When the process is applied to carburized material, the controlling Ms temperature is that of the case. This variation of the process is frequently called marquenching.

Martensite - In steel, a metalstable transition phase with a body-centered-tetragonal crystal structure formed by diffusionless transformation of austenite generally during cooling between the Ms and Mf temperatures.

Martensite - (1) In an alloy, a metastable transitional structure intermediate between two allotropic modifications whose abilities to dissolve a given solute differ considerably, the high-temperature phase transformed to martensite depends to a large extent upon the temperature attained in cooling, there being a rather distinct beginning temperature. (2) A metastable phase of steel, formed by a transformation of austenite below the Ms (or Ar) temperature. It is an interstitial supersaturated solid solution of carbon in iron having a body-centered tetragonal lattice. Its microstructure is characterized by an acicular, or needle-like, pattern.

Martensite Range - The interval between the Ms and Mf temperatures.

Matalloid - (a) Element intermediate in lustre and conductivity between the true metals and non-metals. Arsenic, antimony, boron, tellurium, and selenium, etc., are generally considered metalloids; frequently one allotropic modification of an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn. (b) In steel metallurgy, metalloid has a specialized, even if erroneous, meaning; it covers elements commonly prosent in simple steel; carbon, manganese, phosphorus, silicon and sulfur.

Matrix - The principal phase or aggregate in which another constituent is embedded.

Matrix - The principal phase in which another constituent is embedded.

Mechanical Polishing - A method of producing a specularly reflecting surface by use of abrasives.

Mechanical Properties - The properties of a material that reveal its elastic and inelastic behavior where force is applied, thereby indicating its suitability for mechanical application; for example, modulus of elasticity, tensile strength, elongation, hardness, and fatigue limit.

Mechanical Properties - Those properties of a meterial that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength and fatigue limit. These properties have often been designated as physical properties, but the term mechanical properties is much to be preferred. The mechanical properties of steel are dependent on its microstructure.

Mechanical Spring - Any spring produced by cold forming from any material with or without subsequent heat treatment.

Mechanical Twin - A twin formed in a metal during plastic deformation by simple shear of the structure.

Medium-Carbon Steel - Contains from 0.30% to 0.60% carbon and less than 1.00% manganese. May be made by any of the standard processes.

Melting Point - The temperature at which a pure metal, compound or eutectic changes form solid to liquid; the temperature at which the liquid and the solid are in equilibrium.

Melting Range - The range of temperature in which an alloy melt; that is the range between solidus and liquidus temperatures.

Metallography - The science concerning the constituents and structure of metals and alloys as revealed by the microscope.

Metalograph - An optical instrument designed for both visual observation and photomicrography of prepared surfaces of opaque materials at magnifications ranging from about 25 to about 1500 diameters.

Metastable - Possessing a state of pseudo-equilibrium that has a free energy higher than that of the true equilibrium state but from which a system does not change spontaneously.

Mf Temperature - The temperature at which martensitic transformation is essentially complete during cooling after austenitization.

Microcrack - A crack of microscopic size.

Micrograph - A graphic reproduction of the prepared surface of a specimen at a magnification greater than ten diameters. When photographed, the reproduction is known as a photomicrograph (not a microphotograph).

Microstructure - The structure of a prepared surface of a metal as revealed by a microscope at a magnification greater than ten diameters.

Microstructure - The structure of polished and etched metal and alloy specimens as revealed by the microscope.

Mild Steel - Carbon steel containing a maximum of about 0.25% C.

Mill Edge - The edge of strip, sheet or plate in the as rolled state. Unsheared.

Modulus of Elasticity - A measure of the rigidity of metal. Ratio of stress, within proportional limit, to corresponding strain. Specifically, the modulus obtained in tension or compression is Young's modulus, stretch modulus or modulus of extensibility; the modulus obtained in torsion or shear is modulus of rigidity, shear modulus or modulus of torsion; the modulus covering the ratio of the mean normal stress to the change in volume per unit volume is the bulk modulus. The tangent modulus and secant modulus are not restricted within the proportional limit; the former is the slope of the stress-strain curve at a specified point; the latter is the slope of a line from the origin to a specified point on the stress-strain curve. Also called elastic modulus and coefficient of elasticity.

Mold - A form of cavity into which molten metal is poured to produce a desired shape.

Ms Temperature - The temperature at which a martensitic transformation starts during cooling after austenitization.

Muntz Metal (A refractory Alloy) - Alpha-beta brass, 60% copper and 40% zinc. Stronger than alpha-brass and used for castings and hot-worked (rolled, stamped, or extruded) products. High strength brasses are developed from this by adding other elements.