The original length of that portion of the specimen over which strain or change of length is determined.
Reference marks; in tensile testing, the marks which indicate the gage length, used in determination of tensile elongation.
A metal piece of irregular shape (usually an L shape) used to reinforce and support sand in deep pockets of molds. There are two types; straight or hooked (cast or steel rods).
Checking dimensional requirement by means of a gage.
One of the allotropic (polymorphic) forms of iron which crystallizes in the face-centered-cubic lattice form. When pure, its range of stability is from 1,670°F to 2,552°F (910°C to 1400°C).
An acid (silicious) refractory often used in furnace linings.
Rounded cavities caused by generation or accumulation of gas or entrapped air in a casting; holes may be spherical, flattened or elongated.
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.
Specifically, the point at which molten metal enters the casting cavity. Sometimes employed as a general term to indicate the entire assembly of connected columns and channels carrying the metal from the top of the mold to that part forming the casting cavity proper. This term is also applied to pattern parts that form the passages, or to the metal that fills them.
Natural black lustrous asphalt found in the Uinta Mountains in Utah and also known as uintaite. It is used as a carbonaceous addition to foundry sands.
The pressure vessel or metal injection mechanism in a hot-chamber-type die-casting machine.
Abrasion involving gross surface indentation and possible removal of sizable metal fragments.
The grade of an iron, usually given by three successive numbers, the first being the tensile strength (KSI), the second the yield strength (KSI), and the third the elongation (%).
Grain Fineness Number
A system developed by AFS for rapidly expressing the average grain size of a given sand. It approximates the number of meshes per inch of that sieve that would just pass the sample if its grains of uniform size. It is approximately proportional to the surface area per unit of weight of sand, exclusive of clay.
Any material added to a liquid metal or alloy or treatment which produces a finer grain size in the subsequent solid.
Crystals in metals and alloys.
Granular Fracture (Crystalline fracture)
A type of irregular surface produced when metal is broken.
A structure formed from ordinary lamellar pearlite by long annealing at a temperature below but near to the critical point, causing the cementite to spheroidize in a ferrite matrix.
Native carbon in hexagonal crystals, also foliated or granular massive, of black color with metallic luster, and soft. Used for crucibles, foundry facings, lubricants, etc. Also made artificially by passing alternating current through a mixture of petroleum coke and coal tar pitch. See Coke, Crucible.
Carbon precipitated as graphite flakes while the iron cools through the freezing eutectic in which austenite, graphite, molten iron, and carbide exist together. Usually with reference to white fracture cast iron.
Graphite formed by decomposition of austenite during slow cooling of cast iron.
The decomposition of carbide to give free carbon as graphite or as temper carbon.
Any substance, such as silicon, titanium, aluminum, etc., which promotes the formation of graphite in cast iron compositions.
Iron in which a large percentage of the carbon content is in the form of graphite flakes. Traditionally referred to as “Cast Iron”. The graphite flakes cause it to have low shock resistance, but high damping ability. It has a gray fracture. Gray Iron is by far the oldest and most common form of cast iron. As a result, it is assumed by many to be the only form of cast iron and the terms “cast iron” and “gray iron” are used interchangeably. Cast iron containing graphite in flake form and typically consisting of 2 to 4 percent carbon and 1 to 3 percent silicon. Gray iron is widely used for engine components in automobiles and trucks. See Cast Iron.
Gray Iron Meltimg
The process of melting gray iron, especially as it is done in a foundry on a commercial scale. See Gray Iron.
Gray Iron Quality Control
The application of quality control practices to the manufacture of gray iron. See Gray Iron.
Property of a molded mass of sand in its tempered condition which is a measure of its ability to permit the passage of gases through it.
Green Sand Core
A core that is made of molding sand but not baked.
Tenacity (compressive, shear, tensile, or transverse) of a tempered sand mixture at room temperature.
With reference to cast iron, permanent increase in volume that results from continued or repeated cyclic heating and cooling at elevated temperatures. For unalloyed iron, temperature is in excess of 900° F, and growth is cause by decomposition or graphitization of carbides and by oxidation of the graphite. See Cast Iron.
Calcined calcium sulfate, commonly called plaster of Paris.