Allowance (Tolerance): The clearance specified by the foundry, the difference of limit dimensions, such as the maximum or minimum interference between mating parts calculated by arithmetic.
Alloy: A metal substance composed of two or more chemical elements, containing at least one metal element, usually different from the characteristics of the components.
Alloy Steel: In addition to carbon, steel also contains a large number of alloying elements, as well as recognized content of phosphorus, sulfur, manganese, and silicon.
Alpha – ferrite: Body-centered cubic pure iron with stable properties below 1670°F (910°C).
Alpha Martensite: A form of martensite. In general, it may represent the most twisted and the least developed phase of the transformation from austenite to martensitic at room temperature.
Ambient Temperature: The temperature of the ambient air.
Annealing: The parts are heated to and maintained at a suitable temperature, then cooled at an appropriate rate, so as to change the physical or chemical properties of the parts and reduce the hardness.
Anticarburizing Compounds: Anti-carbonization compounds applied to metal surface.
Acceptable Quality Level.
The level of quality established on a pre-arranged inspection system using randomly selected samples.
Argon Oxygen Decarburization (AOD): A process that can improve the cleanliness of metals and obtain excellent mechanical properties. The principle is to inject argon, oxygen, and nitrogen into molten steel for secondary refining.
Artificial Aging: An aging treatment carried out above normal temperature.
As Cast (as-cast, u.m.): It refers to the metal without surface treatment (except sandblasting or gate removal) or any type of treatment (including post-casting heat treatment).
ASM: American Society for Metals.
ASNT: American Society for Nondestructive Testing.
Austenite: Known as gamma iron, it is the face-centered cubic stage of steel and iron. It represents a solid solution in steel, and gamma iron is the solvent.
Austenite Steel: Any steel containing adequate alloy that can generate a steady austenitic (gamma iron) crystal structure at normal temperature.
Reverse taper in the design direction of extraction from the pattern or core box;
Prevents removal of the pattern from the mold without damaging the mold.
A large amount of sand in a long-necked vase. The sand is compacted onto the face sand that covers the pattern.
Batch: The amount or quantity of core or mold sand or any other material prepared at one time.
Batch Oven: Oven used to bake a bulk number of cores at one time.
Bead: Half-round cavity in a mold, or half-round projection or molding on a casting, a single deposit of weld metal produced by fusion.
BHN: Brinell Hardness Number.
Bimetal: Casting, usually centrifugal casting, made of two different metals, then fused together.
A binder used as an additive to molded or core sand to impart strength or plasticity in the “green” or dry state.
Blacking Carbon: Carbonaceous materials such as plumbago, graphite or powdered coke usually mixed with a binder and frequently carried in suspension in water or other liquid; used as an additive in the mold flux to improved casting finish.
Blasting (Blast Cleaning): The finishing process for cleaning ornamental objects by an air blast or centrifugal wheel that removes abrasive particles against the surface of the workpieces. Small, irregular parts of steel or iron are used as the abrasive in grit blasting, and steel or iron balls in shot blasting.
The riser is not in contact with the atmosphere or does not reach the outside of the mold.
Blister: Blisters, the variant of blowholes, are the shallow blow with a thin film of the metal over it.
Casting defects caused by gas trapped in molten or partially molten metal.
Boil: Agitation of a bath of metal caused by the liberation of a gas beneath its surface. May be deliberately induced by the addition of oxidizing material to a bath containing excess carbon. In the later case it is called a carbon boil and CO or CO2 are liberated.
Bond: Bonding substance or bonding agents – any material other than water, which, when added to foundry sands, imparts bond strength.The overlapping of brick to give both longitudinal and transverse strength.
Bond Strength: Property of a foundry sand to offer deformation resistance. In chemistry, as the strength with which a chemical bond holds two atoms together.
Boring: A machining method uses a stationary, non-rotating cutting tool to remove material from a workpiece.
Boss (Pad): Integral features added to a casting, for a number of potential functions, like mounting. Usually intended for drilling and tapping for attaching parts.
Bottom Running or Pouring: Filling the mold cavity from the bottom by means of gates from the runner.
Bright Annealing: A heat treatment process carried out under a nitrogen-hydrogen atmosphere, so surface does not oxidize, remaining bright.
Brinell Hardness: It indicates the ability of a metal to resist permanent indentation deformation. The value of hardness of a metal on an arbitrary scale representing kg/mm², calculated by measuring the diameter of the impression made by a ball of given diameter applied under a known load. Values are expressed in Brinell Hardness Numbers, BHN.
Brittle Fracture: Fracture of a metallic object or other material without appreciable prior plastic deformation.
Indentation in the casting due to expansion of the sand, which can be called the beginning of expansion defects.
Bulk Density: The ratio of the weight of a material to its total volume (including any inherent porosity).
Burnt-On-Sand: A misnomer usually indicating the mixture of sand and metal on the surface of a casting due to metal penetration of the sand mold. It mainly occurs in think-walled, heavy castings or at the points with the highest temperatures.
Burnishing: Developing a smooth finish and micro-hardness by tumbling or rubbing metal with a small hard tool to compact the surface.