The Glossary of Foundry and Casting
(J-K-L-M-N)

To help metal casting buyers and sellers to understand more about metal casting and foundry operation terms. All terms have been arranged in alphabetical order.

A-B  C-D-E  F-G-H-I  J-K-L-M-N  O-P-Q-R-S-T  U-V-W-X-Y-Z

Jack Arch
A spring arch, flat or horizontal on the underside.

Jacket, Mold
A wood or metal form slipped over a mold made in a snap or slip flask, to support the four sides of the mold during pouring. Jackets and mold weights are shifted from one row of molds to another during the pouring period. See Flask.

Jamb
Usually an upright structural member forming the side of an opening in a refractory or furnace wall.

Jamb Brick
A brick modified so one corner is rounded.

Jar Ramming
Packing sand in a mold by raising and dropping on a table the sand, pattern, and flask. Jolt squeezers, jarring machines, and jolt rammers are machines using this principle. See Jolt Ramming, Jolt Squeezer Machine, Jolt Machine.

Jarring Machine
A molding machine that packs the sand by jarring. See Jar Ramming.

Jersey Fireclay Brick
Highly siliceous clay brick, semisilica brick.

Jet Scrubber
A high velocity water jet directed into the throat of a venture section of a cupola to separate out particulates in air pollution control.

Jet Tapping
A method of tapping a melting furnace by firing a small explosive charge instead of using an oxygen lance. The tapper consists of an explosive charge enclosed in a plastic case surrounded by a hollow bullet-shaped body.

Jib
Projecting part of crane from which lifting chain or gear is suspended.

Jig
A device arranged to expedite a hand or machine operation.

J-Integral
A mathematical expression used to characterize the fracture toughness of a material having appreciable plasticity prior to fracture. The J-integral eliminates the need to describe the behavior of the material near the crack tip. Units are MN/m or in in-lb/in 2.

Jobbing Foundry
A foundry engaged in the manufacture of numerous types of castings and is not a part of a manufacturing plant, and produces castings for sale that usually makes a wide variety of castings in small lots or quantities. See Casting, Foundry.

Joint Welding
Production welding used to weld cast components together to obtain an integral unit.

Jolt
To raise the flask filled with sand and allow it to drop, thereby compacting the sand against the pattern. See Flask, Sand.

Jolt Machine
Molding machine which packs or rams the sand around the pattern by raising the table on which the flask, sand, and pattern are mounted a few inches and allowing the whole to drop suddenly. The table is raised pneumatically, and the operation is repeated until the desired sand density is reached.

Jolt Ramming
Packing sand in a mold by raising and dropping the sand, pattern, and flask on a table. Jolt squeezers, jarring machines, and jolt rammers are all machines that use this method.

Jolt Squeezer Machine
A combination machine that employs a jolt action followed by a squeezing action to compact the sand around the pattern. See Jar Ramming.

Jominy Test
See End-Quench Hardenability Test.

K Factor
Tensile strength in pounds per square inch divided by the Brinell Hardness number. See BHN, Brinell Hardness.

Kahlbaum Iron
An iron of more than 99.975% purity, produced in Germany.

Kalling-Dommarfvet process
A desulfurizing process using powdered burnt iron.

Kaolin
The purest form of China clay consisting of silicate of aluminum.

Kaolinite
Hydrated silicate of alumina represented by the formula Al2O3 • 2 SiO2 2 H2O. It is a white, pearly mineral, crystallizing in a monoclinic system in the form of small, hexagonal plates. Constituent of kaolin, white china clay, used for porcelain, etc.

Kappa Carbide
A carbide of iron (Fe23,C6) in which all or part of the iron may be replaced by chromium, molybdenum, and/or tungsten.

Kayser Hardness Test
A method for determining the true hardness of metals at high temperatures.

KC (Plane-stress fracture toughness)
The value of stress intensity at which crack propagation becomes rapid in sections thinner than those in which plane-strain conditions prevail. Units are MPa/m or ksi/in.

Kelvin Temperature Scale
One in which the unit of measurement equals that of the centigrade degree and according to which absolute zero is 0 degrees, equivalent to -273.16°C.

Kerf
The width of a cut.

Keyhole Specimen
A type of notched impact test specimen which has a hole-and-slot notch shaped like a keyhole.

Kic (Plane-Strain Fracture Toughness)
The minimum value of KC. Represents the fracture toughness of a material independent of crack length, or loading system. Units are MPa/m or ksi/in.

Kieselguhr
Diatomaceous earth, a finely porous material used for thermal insulation to 1100°C (2012°F).

Killed Steel
Molten steel held in a ladle, furnace, or crucible (and usually treated with aluminum, silicon, or manganese) until more gas is evolved and the metal is perfectly quiet. See Crucible, Ladle.

Kiln
An oven or furnace for burning, calcimining or drying a substance.

Kiln Marks
Irregularities on the surface of refractors caused by deformation under load during burning.

Kiln-Dried
Lumber artificially dried in a specially designed enclosure or lumber kiln.

Kilovolt (kV)
Unit of electrical potential equal to 1,000 volts.

Kilovolts Constant Potential
The potential in kilovolts of a constant voltage generator.

Kilovolts Peak
The crest value of the potential wave in kilovolts. When only one half of the wave is used, the crest value is to be measured on this half of the wave.

Kip
A term sometimes used to represent a unit load of 1,000 pounds.

Kish
Graphite thrown out by liquid cast iron in cooling.

Kissing (Touching)
Gating with minimum metal left at casting breakoff point, having a gate just "kiss" the surface. See Gate.

Knock Out
To remove sand and casting from a flask.

Knock-Off Riser
Riser with a small attachment and can be knocked off with a hammer.

Knock-Out Pins
Small pins on die-casting machines, permanent molds, and shell-molding machined for ejection of castings, etc. See Ejector Pins.

Knoop Hardness Number (HK)
A number related to the applied load and to the projected area of a rhombic-based diamond indentor, with edge angles of 172 1/2° 30' and 130 1/2°.

Ladle
Metal receptacle frequently lined with refractories used for transporting and pouring molten metal. Different types of ladles include hand bull, crane, bottom-pour, holding, teapot, shank, lip-pour.

Ladle, Bottom-Pour
Ladle from which metal flows through a nozzle in the bottom.

Ladle, Bull
Large ladle for transporting and pouring molten metal.

Ladle, Lip-Pour
Ladle in which the metal is poured over a lip.

Ladle, Teapot
A ladle in which, by means of an external spout, metal is removed from the bottom rather than the top of the ladle. See Ladle.

Lance, Oxygen
Long steel pipe or tube, usually covered with refractory, used to inject oxygen into molten steel to reduce the carbon content. Also may be used to open up frozen tap holes in cupolas, etc. See Cupola.

Lap-Gate
When the connection point of ingate to casting overlaps onto the cope surface.

Lateral Expansion
A measured property used in Charpy Impact Testing. Refers to the increase width of the specimen after fracture. See Charpy Impact Testing.

Leaker
Foundry term for castings which leak under liquid or gaseous pressure.

Linear Elastic Fracture Mechanics (LEFM)
A method of fracture analysis that can determine the stress required to induce fracture instability in a structure with a crack like flaw of know size and shape.

Lining
Inside refractory layer of firebrick, clay, sand, or other material in a furnace or ladle.

Lining, Monolithic
A lining made without the customary layers and joints of a brick wall. Usually made by tamping or casting refractory material into place, drying, and then burning in place on the job.

Linseed Oil
Drying-type oil expressed from flax seeds and used as a binder for core sand. See Binder, Core Sand.

Liquid Contraction
Shrinkage or contraction in molten metal as it cools from one temperature to another while in the liquid state.

Liquid Penetrant Testing
A nondestructive testing method suitable for evaluating the surface integrity of non-magnetic and ferro-magnetic parts.

Liquidus
The temperature at which solidification of metal begins on cooling and the temperature at which the last portion of solid metal becomes liquid on heating.

Loam
A coarse, strongly bonded molding sand used for loam and dry-sand molding.

Loam Mold
A mold built up of brick, covered with a loam mud, and then baked before being poured.

Loam Molding
A system of molding, especially for large castings, wherein the supporting structure is constructed of brick. Coatings of loam are applied to form the mold face.

Locating Pad
A projection on a casting that helps maintain alignment of the casting for machining operations.

Locating Surface
A casting surface to be used as a basis for measurement in making secondary machining operations.

Logo
The sign, mark, or distinguishing letter designating the manufacturer.

Loose Molding
The molding process utilizing unmounted patterns. Gates and runners are usually cut by hand. See Gates, Runners.

Loose Piece
Part of a pattern so attached that it remains in the mold, and is removed after the body of the pattern is drawn. In die-casting, a type of core, (which forms the undercuts, positioned in, but not fastened to, a die and so arranged as to be ejected with the die-casting, from which it is removed and used repeatedly for the same purpose. See Core Box, Pattern.

Loose Pieces
Part of a core box or pattern which remains embedded in the core or mold and is removed after lifting off the core box or drawing the pattern. Backdraft is avoided by this means. See Core Box, Pattern.

Lost Foam Process
Casting process in which a foam pattern is removed fro the cavity by the molten metal being poured. See Mold Cavity.

Lost Wax Process
A method for changing a sculpture made of soft clay into a harder material, such as bronze.

Low Stress Scratching Abrasion
Abrasion involving near zero impingement angle for the striking particle, also parallel flow erosion.

Machinability
The capability of being cut, turned, broached, etc., by machine tools.

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. See Computer Aided Design (CAD).

Machine Finish
Allowance of stock on the surface of the pattern to permit the machining of the casting to the required dimensions.

Magnaflux™
Trade name for a method of magnetic crack detection.

Magnaglo™
Trade name for a method of magnetic crack detection in which the magnetic particles are treated so that they fluoresce in ultraviolet light.

Magnetic Crack Detection
Method of locating cracks in materials which can be magnetized; done by applying magnetizing force and applying finely divided iron powder which then collects in the region of the crack.

Magnetic Particle Inspection
A nondestructive method of inspecting the surface integrity of ferromagnetic materials.

Malleability
The property of being permanently deformed by compression without rupture.

Malleable Iron
Iron that may be altered in shape by hammering or by the pressure of rollers without exhibiting fracture or brittleness. The majority of the carbon content is in the form of graphite nodules rather than flakes. See Nodular Iron.

Malleableization
Annealing or heat-treating operation performed on white iron castings to transform the combined carbon into temper carbon.

Manganese
One of the elements; its chemical symbol is Mn. It’s formula weight is 54.93; specific gravity 7.2, and melting point is 1260°C. Metallic manganese is used in the nonferrous industry both as a deoxidizing agent and as an essential constituent to improve physical properties of certain alloys.

Manganese Briquets
Crushed ferromanganese bonded with a special refractory in briquet form, and containing 2-lb metallic manganese and ½-lb metallic silicon.

Manganese Steel (Austenitic)
See Hadfield Manganese Steel.

Maraging Steel
A high alloyed steel that is hardened by both martensite transformation and by age hardening. See Age Hardening, Martensite.

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. See Austenite, Martensite, Quenching.

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

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.

Master Pattern
An original pattern made to produce castings which are then used as metal patterns. See Casting.

Match
A form of wood, plaster of Paris, sand or other material on which an irregular pattern is laid or supported while the drag is being rammed.

Matchplate
A metal or other plate on which patterns split along the parting line are mounted back to back with the gating system to form an integral piece.

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

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. This term should not be used interchangeably with "physical properties."

Melting Pot
Metal, graphite-clay, or ceramic vessel in which metal is melted.

Melting Range
Pure metals melt at one definite temperature, but constituents of alloys melt at different temperatures, and the variation from the lowest to the highest is called the melting range. See Alloy.

Melting Rate
Amount of metal melted in a given period of time, usually one hour.

Melting Zone
Portion of the cupola above the tuyeres in which the metal melts. See Cupola, Tuyeres.

Metal Lot
A master heat that has been approved for casting and given a sequential number by the foundry.

Metal Penetration
Defect in the casting surface which appears as if the metal has filled the voids between the sand grains without displacing them.

Metalloid
An element intermediate between metals and nonmetals possessing both metallic and nonmetallic properties, as arsenic, 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
Science dealing with the constitution, structure, and properties of metals and alloys, and the processes by which they are obtained from ore and adapted to the use of man.

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-Al 2O3.

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. See Brinell Hardness, Charpy Impact Test.

Mf
The temperature at which martensite formation finishes during cooling. See Martensite, Ms.

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.

Micro Pipes (British) (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.

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

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.

Micrography
Examination by means of a microscope.

Microhardness
The hardness of microconstituents of a material. See Hardness.

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

Microporosity
Extremely fine porosity in castings caused by shrinkage or gas evolution and apparent on radiographic film as mottling. See Microshrinkage.

Microradiography
Process of passing x-rays through a thin section of an alloy in contact with photographic film, and then magnifying the radiograph 50 to 100 diameters to observe the distribution of alloying constituents, of voids, and of other microstructural features. See X-rays.

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. See 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. See Spectography.

Microstructure
The structure and characteristic condition of metals as revealed on a ground and polished (etched or unetched) specimen at magnifications above 10 diameters. See Microsection.

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

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

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

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

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

Mild Steel
Plain carbon steel of about 0.25% carbon or less.

Mill Sale
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.

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

Milliscope (British)
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.

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

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

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.

Mitis Casting
Casting of very mold steel.

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.

Modulus Of Elasticity (E)
In tension it is the ration of stress to the corresponding strain within the limit of elasticity (Yield Point) of a material. For carbon and low alloy steels any composition and treatment, the value is approximately 30,000,000 psi.

Modulus of Resilience ( ur )
The amount of strain energy per unit volume required to tress 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. See Porosity.

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°F - 230°F (104.4°C - 110°C).

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. See Sand Molding.

Mold
Normally consists of a top and bottom form, made of sand, metal, or any other investment material which contains the cavity into which molten metal is poured to produce a casting of definite shape and outline. See Mold Cavity.

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 impression in a mold produced by removal of the pattern. It is filled with molten metal to form the casting. Gates and risers are not considered part of the mold cavity. See Casting, Gates, Risers.

Mold Coating
Coating to prevent surface defects, i.e., metal penetration and improve casting finish. See Core Wash.

Mold Conveyor
Power-driven unit on which molds are conveyed from the molding station to pouring station to shakeout.

Mold Cover Half (Cover Die)
The top half of the mold, the cope. In die casting, the front half of the die, which remains stationary as the die is opened. See Cope.

Mold Facing
See Mold Coating.

Mold Hardener
In sand molds in which sodium silicate is the binder, injection of CO2 causes a chemical reaction which results in a rigid structure.

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

Mold Oven
Oven or furnace in which molds are dried.

Mold Shift
Casting defect resulting when the two cavities in the cope and drag molds do not match properly. See Cavity, Mold Cavity, Cope, Drag.

Mold Wash
Usually an aqueous emulsion, containing various organic or inorganic compounds or both, which is used to coat the face of a mold cavity. Materials include graphite, silica flour, etc. This guards against penetration of metal into sand walls.

Mold Weights
Weights placed on top of molds to offset internal or ferrostatic pressure.

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. See Flask, Pattern.

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

Molding Bench
The making of sand molds from loose or production patterns at a bench.

Molding Floor
Making sand molds from loose or production patterns at a floor. Patterns are usually too large to be handled satisfactorily on the bench. See Sand Molding, Molding Sand.

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

Molding Machine
Hand or pneumatically operated machine on which molds are made and which rams the sand by squeezing or jolting or both.

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

Molding Sand
Mixture of sand and clay suitable for mold making.

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 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, Machine
Making sand molds from production patterns on molding machines. See Sand Molding.

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

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
A metal used widely in alloying of other metals. It is used as hardening element for steel, and for diecasting dies. The melting point is 2,620°C (4,748°F), and the atomic number is 42.

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. See Inconel.

Monitoring
Periodic or continuous determination of the does rate in an occupied area (area monitoring) or the does received by a person. See Monitoring, Personnel.

Monitoring, 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 (British)
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. See Flask.

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.

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

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

Moisture, 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. See Alloy, Solidification.

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

Mottled
White iron structure interspersed with spots or flecks of gray.

Mottled Cast Iron
Iron which consists of a mixture of variable proportions of gray iron and white cast iron. Mottle cast ironhas a mottled fracture. See Gray Iron, White Cast Iron.

Mould (British)
Normally consists of a top and bottom form, made of sand, metal, or any other investment material which contains the cavity into which molten metal is poured to produce a casting of definite shape and outline. The American spelling of this word is "mold". See Mold.

Mould Cavity (British)
The impression in a mould produced by removal of the pattern. It is filled with molten metal to form the casting. Gates and risers are not considered part of the mould cavity. See Mold Cavity.

Mould Coating (British)
Coating to prevent surface defects and improve surface finish. See Mold Coating.

MP
Abbreviation for 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 Daubing.

Mud daub
See Daubing.

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.

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.

Muller
Type of foundry-sand-mixing machine. See Foundry Sand.

Mulling
The thorough mixing of sand, water and binding ingredients to form tempered ready-to-use molding or core sand. See Core Sand.

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

Multiple Mold
Composite mold made up of stacked sections. Each section produces a complete gate of castings. All castings are poured from a central downgate.

Multiple-Cavity Die
A die-casting die having more than one impression of the same part. See Combination Die.

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.

Nail, Chill
Steel nail with a heavy head which is inserted in the mold wall to hasten cooling of the metal at that point.

Natural Aging
See Aging.

Natural Sand
Unconsolidated sand, sand derived from a rock in which grains separate along their natural boundaries. This includes soft sandstone where little pressure is required to separate the individual grains. See Molding Sand, Naturally Bonded Molding Sand.

Naturally Bonded Molding Sand
A sand containing sufficient bonding material as mined to be suitable for molding purposes. Seldom used today in the metalcasing industry. See Molding Sand.

Navy (USA) Tear Test
A method of evaluating the susceptibility of ship plate to brittle or cleavage type fracture.

Neat Brick
Brick with faces arranged so one of the flat faces in inclined toward the other, almost eliminating one end face.

Neat Cement
Portland Cement mixed with water only.

Neck Down (Knock-Off, Wafer Core, Washburn, Cameron Core)
A thin core or tile used to restrict the riser neck, making it easier to break or cut off the riser from the casting. See Core.

Necking
Reducing the cross sectional area of the metal in an area by stretching.

Necking Down
Reduction in area concentrated at the subsequent location of fracture when a ductile metal is stressed beyond it yield point in tension.

Needles
Elongated acicular crystals, tapering at each end to a fine point, as martensite.

Needling Agents
Special agents such a boron which markedly increase the hardness of steel.

Negative Quenching (Negative Hardening)
Accelerated cooling in water or oil, from a temperature below the critical range. See Quenching.

Negative Thermoie Heat Exchange
In shell molding, improving the mass-surface ratio by simulating profile geometry of pattern or core cavity on the underside; will boost running temperature of high projections by 25%. See Shell Molding.

Nesh (Hot Short)
A British term applied to metal that is weak and ruptures easily under not working conditions.

Network Structure
A structure in which the grains or crystals of one constituent are partly or entirely enveloped in another constituent; an etched section through the crystals resembles a network.

Neumann Band
A mechanical twin in ferrite.

Neutral Refractories
A loose term designating refractories which presumably will not react with so-call acid or basic refractories and slags. See Refractory, Slag.

Neutron
Elementary nuclear particle with a mass (1.00893 mass units) approximately the same as that of a hydrogen atom. It is electrically neutral.

New Jersey Sand
A large number of grades of foundry sands mined in southern New Jersey.

Nichrome
Oxidation-resistant alloy 65% Ni, 20% Fe, and 15% Cr.

Nickel
An element used for alloying iron and steel as well as nonferrous metals; melting point 1455°C (2651°F). Nickel is also a base metal for many casting alloys resistant to corrosion and high temperature oxidation. Nickel’s chemical symbol is Ni. Its formula weight is 58.69, the specific gravity is 8.90, and nickel’s melting point 1,452°C. See Monel, Nimonic, Inconel, Ni-Hard.

Ni-Hard
Hard white cast iron containing 4% Ni and 2% Cr. See White Cast Iron.

Nil Ductility Transition Temperature (NDDT)
Determined in the dropweight test. Refers to the absence of the ductile fracture appearance and any reduction in area due to the brittle behavior of the steel. See Ductility.

Nimonic
Class of nickel-base cast alloy resistant to stress and to oxidation at high temperatures. See Inconel.

Nine-Inch Equivalent
Standard unit of volume in refractories industries; 9 x 4-1/2, 2-1/2 in brick.

Nipple
A pipe coupling consisting of a short piece of threaded tubing.

Nital
A solution of nitric acid in alcohol use as an etching agent in ferrous metallography.

Nitriding
A surface hardening process involving heating in a atmosphere of ammonia or in contact with a nitrogen-bearing material so as to promote the absorption of nitrogen.

Nitrogen Flush
Bubbling nitrogen gas through a metal melt under vacuum (as with valve bronze) to improve tensile properties and pressure tightness.

Nobake Binder
A synthetic liquid resin sand binder that hardens completely at room temperature, generally not requiring baking, used in the Cold Setting process. See Cold Setting Process.

No-Bake Process
Molds/cores produced with a resin bonded air setting sand. Also known as the air set process because molds are left to harden under normal atmospheric conditions. See Core, Mold.

Noble Metals
Metallic elements with surfaces that do not readily oxidize in air; e.g., gold, silver, platinum.

Nodular Fireclay (Burley, Burley Flint)
Rock containing aluminous or ferrogenous nodules, or both, bonded by fireclay.

Nodular Graphite
Graphite or carbon in the form of spheroids, characteristically in malleable and nodular iron.

Nodular Iron
Cast iron, normally gray cast iron, which has the major part of its graphitic carbon in nodular from. See Ductile Iron.

Noise Radiator
A device creating noise.

Noise Spectrum
The various frequencies making a noise.

Nomogram (Graph)
A graph that enables one by the aid of a straight-edge to read off the value of a dependent variable when the value of two or more independent variables are given.

Nondestructive Testing (Inspection)
Testing or inspection that does not destroy the object being tested or inspected.

Nonferrous
A negative term, refers to alloy in which the predominate metal or solvent is not iron. See Alloy.

Nonferrous Metal Casting
Metal casting done with a nonferrous metal, in which the molten metal is poured into a mold, cooled, and allowed to solidify. See Nonferrous.

Nonferrous Metal Processing
The processing of a nonferrous metal, such as by melting, alloying, or casting. See Nonferrous.

Normal Segregation
Concentration of alloying constituents that have low melting points in those portions of a casting that solidify last.

Normal Steel
Steel in which the pearlite is completely laminated. See Pearlite.

Normalizing
Heating a ferrous alloy to a suitable temperature above the transformation temperature Ac3, followed by cooling at a suitable rate, usually in still air to a temperature substantially below the transformation range.

Notch Bar
Small size ingot with notches to facilitate breakage for remelting.

Notched Bar
A test specimen which is notched. Used in impact or fatigue tests.

Novalak
A two-step basic flake resin with no thermosetting properties, applied to sand in shell molding process as a mold or solution. See Shell Molding.

Nowel
The lower section of the flask, commonly called the drag. See Drag, Flask.

Nozzle
Pouring spout of the bottom-pour ladle. See Ladle.

Nozzle Brick
A thick-walled tubular refractory shape set in bottom of a ladle through which steel is teemed.

Nozzle Pocket Brick
A refractory shape set in bottom of a ladle containing a recess in which nozzle is set. See Ladle.

NTP
Abbreviation for normal temperature and pressure reference point, zero centigrade 760 mm mercury pressure.

Nucleus
The first structurally determinate particle of anew phase or structure that may be about to form. Applicable in particular to solidification, recrystallization, and transformations in the solid state.

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