An individual crystal in a polycrystalline metal or alloy. Grains have various external shapes.

See Intergranular Corrosion.

An increase in the size of grains in a polycrystalline metal, which usually occurs during heating at elevated temperatures. The increase may be gradual or abrupt, resulting in either uniform or non-uniform grains after growth has ceased.

A mixture of non-uniform grains.

Abnormal grain growth implying the formation of excessively large grains.

The abrupt formation of abnormal grain growth when a critical amount of strain or other nuclei are present to promote the growth.

For metals, a measure of the area or volume of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. Grain sizes are given in terms of the number of grains per unit area or volume, the average diameter or as a grain-size number derived from area measurements. They are classified into eight sizes: one to four being coarse, five to eight being fine.

The crystalline structure of the individual grains within a polycrystalline metal. This can be used as an indicator of strength and ductility as well as the uniformity of deformation, heat treatment or elemental dispersion within the material.

A process used to deposit a coating of zinc phosphate onto steel wire or rod prior to dry drawing. Such coatings are extremely retentive of the soap lubricants used in wiredrawing and react with them under the pressure encountered at the die faces to form a smooth film of zinc soaps, which effectively prevents metal to metal contact, thus increasing tool life by minimizing metal pick-up, scratching and breakages. Mainly used for the drawing of high carbon steel. A trademark of Henkel Surface Technologies.

A type of irregular surface, produced when fracture occurs, that is characterized by a rough, grain-like appearance as opposed to a smooth silky or fibrous type. The cracks can propagate in either a transgranular or intergranular mode.

A structure formed by holding steel for some time at a temperature just below the critical, causing the cementite and ferrite in the pearlite to separate into globules.

A machine, which cuts ex­truded plastic into granules for re-use. Recent machines accept hot waste direct from the extruder head without prior cooling and incorporate an air extraction system, which conveys the granules back to the extruder hopper or to a bagging point.

One of the three forms of carbon in nature (the other two are amorphous and diamond). It is one of the softest materials known, is lightweight and has high electrical conductivity. In colloidal form, graphite is being used as a lubricant, and is particularly suitable for hot drawing applications. A disadvan­tage of its use, however, is that dies need cleaning occasionally. It is usually supplied as a colloidal suspension of about 18 percent in water or as a fine suspension in oil, and then diluted with dis­tilled or de-mineralized water. Complete homogenization is of the utmost impor­tance and the lubricant should be thoroughly mixed before use. This lubri­cant is sometimes used for the lubrica­tion of extrusion dies.

Separation of fluids or solids that results from a difference in weight.

An inverted capstan that allows the coils of drawn wire to be deposited by gravity onto an independent receiver.

The draining of coolant from wiredrawing machines so that it will flow by gravity into a holding tank.

Designation for Galvanized Rigid Conduit.

A term used to describe a soap paste used in cold drawing to obtain a clean bright finish. This paste may or may not contain petroleum products, even though the term suggests that it does.

A wire rod that is in the hot-rolled condition prior to any further work being applied to it.

A form of high temperature attack on stainless steel, nickel chromium alloys and nickel chromium alloys subjected to simultaneous oxidation and carburization. Basically, the attack occurs by first precipitating chromium as chromium carbide and then oxidizing the carbide particles.