Acceptable Quality Level. A quality level
established on a prearranged system of
inspection using samples selected at random.
Casting without subsequent heat treatment.
The bulk of the sand in the flask. The sand
compacted on top of the facing sand that covers
bonding agent used as an additive to mold or
core sand to impart strength or plasticity in a
"green" or dry state.
Sand adhering to the surface of the casting that
is extremely difficult to remove.
Chaplet A small
metal insert or spacer used in molds to provide
core support during the casting process.
given weight of metal introduced into the
metal insert in the sand mold used to produce
local chilling and equalize rate of
solidification throughout the casting.
Removal of runners, risers, flash, surplus metal
and sand from a casting.
Cold Shut A
surface imperfection due to unsatisfactory
fusion of metal.
Cope The top
half of a horizontally parted mold.
Core A sand or
metal insert in a mold to shape the interior of
the casting or that part of the casting that
cannot be shaped by the pattern.
An assembly made from a number of cores.
wooden, metal or plastic tool used to produce
projection on a pattern that leaves an
impression in the mold for supporting the core.
Wash A liquid suspension of a
refractory material applied to cores and dried
(intended to improve surface of casting).
displacement of sand at mold joints.
cylindrical, straight shaft furnace (usually
lined with refractories) for melting metal in
direct contact with coke by forcing air under
pressure through openings near its base.
Die A metal
form used as a permanent mold for die casting or
for a wax pattern in investment casting.
Dowel A pin
of various types used in the parting surface of
parted patterns or dies to assure correct
the vertical sides of a pattern or corebox that
permits the core or sand mold to be removed
without distorting or tearing of the sand.
bottom half of a horizontally parted mold.
Movable pins in pattern dies that help remove
patterns from the die.
The sand used to surround the pattern that
produces the surface in contact with the molten
Sometimes referred to as a "riser," it is part
of the gating system that forms the reservoir of
molten metal necessary to compensate for losses
due to shrinkage as the metal solidifies.
The amount of stock left on the surface of a
casting for machining.
A symbol (f, fl, f2, etc.) appearing on the line
of a drawing that represents the edge of the
surface of the casting to be machined or
rigid metal or wood frame used to hold the sand
of which a mold is formed and usually consisting
of two parts, cope and drag.
Metal (of known composition) in the form of
gates, sprues, runners, risers and scrapped
castings returned to the furnace for remelting.
A condition existing in a casting caused by the
trapping of gas in the molten metal or by mold
gases evolved during the pouring of the casting.
The portion of the runner where the molten metal
enters the mold cavity.
Moist clay-bonded molding sand.
single furnace charge of metal.
A combination of heating and cooling operations
timed and applied to a metal or alloy in the
solid state in a manner that will produce
desired mechanical properties.
A resin-based process that uses heated metal
coreboxes to produce cores.
Irregularly shaped fracture in a casting
resulting from stresses set up by steep thermal
gradients within the casting during
Particles of slag, refractory materials, sand or
deoxidation products trapped in the casting
during pouring solidification.
A pattern casting process in which a wax or
thermoplastic pattern is used. The pattern is
invested (surrounded) by a refractory slurry.
After the mold is dry, the pattern is melted or
burned out of the mold cavity, and molten metal
is poured into the resulting cavity.
container used to transfer molten metal from the
furnace to the mold.
A projection on a casting that helps maintain
alignment of the casting for machining
A casting surface to be used as a basis for
measurement in making secondary machining
The object from which a die can be made;
generally a metal model of the part to be cast
with process shrinkage added.
Those properties of a material that reveal the
elastic and inelastic properties when force is
applied. This term should not be used
interchangeably with "physical properties."
Metal Lot A
master heat that has been approved for casting
and given a sequential number by the foundry.
Normally consists of a top and bottom form, made
of sand, metal or any other investment material.
It contains the cavity into which molten metal
is poured to produce a casting of definite
Mold Cavity The
impression in a mold produced by removal of the
pattern. It is filled with molten metal to form
Molds/cores produced with a resin-bonded
air-setting sand. Also known as the airset
process because molds are left to harden under
normal atmospheric conditions.
The line showing the separation of the two
halves of the mold.
wood, metal, foam or plastic shape used to form
the cavity in the sand. A pattern may consist of
one or many impressions and would normally be
mounted on a board or plate complete with a
The taper allowed on the vertical faces of a
pattern to permit easy withdrawal of the pattern
from the mold or die. (see
Full-sized drawing of a pattern showing its
arrangement and structural features.
Shrinkage The shrinkage allowance
made on all patterns to compensate for the
change in dimensions as the solidified casting
cools in the mold from freezing temperature of
the metal to room temperature. The pattern is
made larger by the amount of shrinkage
characteristic of the particular metal in the
casting and the amount of resulting contraction
to be encountered.
The property of a mold material to allow passage
of mold/core gases during the pouring of molten
Properties of matter such as density, electrical
and thermal conductivity, expansion and specific
heat. This term should not be used
interchangeably with "mechanical properties."
Blocks of iron to a known metal chemical
analysis that are used for melting (with
suitable additions of scrap, etc.) for the
production of ferrous castings.
Pilot or Sample Casting
A casting made from a pattern produced in a
production die to check the accuracy of
dimensions and quality of castings that will be
Holes in the casting due to: gases trapped in
the mold, the reaction of molten metal with
moisture in the molding sand, or the imperfect
fusion of chaplets with molten metal.
Ratio of the number of saleable parts to the
total number of parts manufactured, expressed as
Heat-resistant ceramic material.
Ratio of the number of parts scrapped to the
total number of parts manufactured, expressed as
Runner System or Gating
The set of channels in a mold through which
molten metal is poured to fill the mold cavity.
The system normally consists of a vertical
section (downgate or sprue) to the point where
it joins the mold cavity (gate) and leads from
the mold cavity through vertical channels
(risers or feeders).
Cavities or surface imperfections on a casting
caused by sand washing into the mold cavity.
Any scrap metal melted (usually with suitable
additions of pig iron or ingots) to produce
castings; (b) reject castings.
process of separating the solidified casting
from the mold material.
Contraction of metal in the mold during
solidification. The term also is used to
describe the casting defect, such as shrinkage
cavity, which results from poor design,
insufficient metal feed or inadequate feeding.
Slag A fused
nonmetallic material that protects molten metal
from the air and extracts certain impurities
from the melt.
Casting surface imperfections similar to sand
inclusions but containing impurities from the
charge materials, silica and clay eroded from
the refractory lining, and ash from the fuel
during the melting process. May also originate
from metal-refractory reactions occurring in the
ladle during pouring of the casting.
flowable mixture of refractory particles
suspended in a liquid.
Process Molding sand is mixed with
sodium silicate and the mold is gassed with CO2
gas to produce a hard mold or core.
The channel, usually vertical, that the molten
Standard specimen bar designed to permit
determination of mechanical properties of the
metal from which it was poured.
Test Lug A
lug cast as a part of the casting and later
removed for testing purposes.
opening or passage in a mold or core to
facilitate escape of gases when the mold is