- Manganese Steel (Austenitic)
- See Hadfield Manganese Steel
- Machine Allowance
- Stock added to the part to permit machining of the part to
- Machine Drawing
- An engineering drawing which depicts the final size and shape
of the part for its end use.
- Magnetic Particle Inspection
- A nondestructive method of inspecting the surface integrity of
- Maraging Steel
- A high alloyed steel that is hardened by both martensite
transformation and by age hardening.
- 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.
- 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 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
- 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.
- Meallographic Structure
- The nature, distribution, and amounts of the metallographic
constituents in a metal.
- Mechanical Properties
- Properties of a material that reveal its strength and elastic
- 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
- 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.
- 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
- 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.
- 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%
- 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.
- The temperature at which martensite formation finishes during
- 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
- Michigan Sand
- Core sands of dune or lake sand and bank sands found in Michigan.
- 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.
- Microcast Process
- A patented method of precision-casting alloys, as Vitallium, Monel,
Inconel and the Haynes Stelite alloys.
- Etching of metal samples for examination under the microscope.
- A type of extensometer for measuring elongation of test piece in a
- Examination by means of a microscope.
- The hardness of microconstituents of a material.
- 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.
- A test coupon used to give rapid indication of the effectiveness
of magnesium treatment of ductile iron.
- See Microshrinkage
- 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.
- Minute object or structures which are invisible or not clearly
distinguished without the use of a microscope.
- A metal specimen whose surface has been polished and etched to
reveal the microstructure.
- 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.
- A method of identifying metallic constituents using spectrographic
- The structure of polished and etched metal and alloy specimens as
revealed by the microscope at magnifications over 10 diameters.
- A low load hardness tester, suitable for both Vickers and Knoop
tests, working with loads of between 10 to 3000 grams.
- Microtone (Brit.)
- An instrument for cutting thin sections of soft specimens.
- Migra Iron (Brit.)
- A special pig iron for high quality castings.
- 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.
- Mild Steel
- Plain carbon steel of about 0.25% carbon or less.
- 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.
- Removing metal with a milling cutter.
- 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.
- 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
- An alloy of rare earth metals containing about 50% lanthanum,
neodymium, and similar elements.
- Solubility; ability of two or more liquids to form a homogeneous
- 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
- Mitis Casting
- Casting of very mold steel.
- A full-size model built accurately for study, testing or display.
- A proportional representation of an object in any scale.
- Modell Number
- A value giving a measure of wear resistance.
- 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 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.
- Equipment for sealing by vacuum impregnation of small pores in
- 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°F (104.4 - 110°C).
- Moisture Teller
- A patented apparatus for the rapid determination of moisture
content of molding sand.
- 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.
- 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
- 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
- Mold Clamp
- Devices used to hold or lock cope 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
- Mold Facing
- See Mold Coating
- Mold Jacket
- A wooden or metal form slipped over a mold to support the side
- Mold Shift
- A casting discontinuity resulting from misalignment of the cope
and drag halves.
- Ability of sand to flow into a flask and around a pattern;
measured in the amount of sand falling through an inclined screen
- Moldabilty Controller
- A patented device for controlling water additions to sand mix to
maintain a consistent moldability index.
- 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 Gravel
- The coarser and more permeable grades of molding sand generally
used in production casting of exceptional size and weight.
- Molding Material
- A material suitable for making molds into which molten metal can
- Molding, Pit
- Molding method in which the drag is made in a pit or hole in the
- 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
- Molecular Weight
- Weight of the smallest quantity of a substance processing all its
normal physical properties.
- The smallest particle of a substance that can exist in the free
state and which has the same composition as any larger mass of
- A metal used widely in alloying of other metals. It is used as
hardening element for steel, and for diecasting dies. Melting
point 2620°C (4748°F), atomic number 42.
- Molybdic Oxide
- The oxide of molybdenum; added to the furnace in briquetted form
as an important finishing constituent in nitriding steels.
- 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.
- 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.
- An isothermal reversible reaction in a binary system, in which a
liquid on cooling, decomposes into a solid and a second liquid of
- An instrument for measuring indentation hardness. It is fitted
with two dials, one to measure depth of penetration, the other
- 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.
- 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.
- Melting point.
- The temperature at which transformation of austenite to martensite
starts during cooling.
- A term frequently used to designate plastic lining materials.
See also 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
- 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.
- 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.
- Multiple Mold
- A composite mold made up of stacked sections, each of which
produces a complete gate of castings, and poured from a central
- Mushet Steel
- An air hardened steel containing about 2% c, 2% Mn, and 7% W,
developed by Scotsman Robert Mushet in 1870.
- Mushy Stage
- The state between sold and liquid in alloys which freeze over a
wide range of temperatures.