Forging Terms and Definitions: J-R

From Machine forging to Rib-and-web forging
Courtesy of Forging Industry Association

Machine forging (upsetter forging): one made in a forging machine or upsetter, in which a horizontally moving die in the ram forces the alloy into the die cavities.

Mandrel forging: see saddle/mandrel forging.

Match: aligning a point in one die half with the corresponding point in the opposite die half.

Microalloyed-steel forging: one made from a mircroalloyed steel requiring only controlled cooling to reach optimum properties, which is in contrast to conventional quenched-and-tempered steels that require traditional heat treatments to achieve the same results.

Microstructure: the microscopic structure of metals/alloys as seen on a mounted, ground, polished and etched specimen to reveal grain size, constituent phases, etc.

Near-net-shape forging: forging components as close as possible to the required dimensions of the finished part.

Open die forging: one produced by working between flat or simply contoured dies by repetitive strokes and continuous manipulation of the workpiece; sometimes called hand forging.

Parting line: the plane that divides the two die halves used in forging; also applies to the resulting forging and impression dies.

Piercing: forming or enlarging a hole via a tapered or cylindrical punch.

Plastic deformation: permanent distortion of a material without fracturing it.

Plate: a flat, hot-rolled metal or alloy product whose thickness is much less than its width.

Precision forging: any forging process that produces parts to closer tolerances than conventional forging processes.

Preform: forging operation in which stock is preformed or shaped to a predetermined size and contour prior to subsequent die forging operations; also, ring blanks of a specific shape for profile (contour) ring.

Press forging: the shaping of metal between dies on a mechanical or hydraulic press.

Quenched-and-tempered steel forging: one that is quenched and tempered to produce the required forging hardness and properties; should more accurately be referred to as hardened-and-tempered. (Hardening and tempering are heat treatments that follow austenitizing, which is usually the first heat treatment performed on carbon- and alloy-steel forgings.

Restriking: a salvage operation following a primary forging operation - rehitting forgings in the same die in which they were last forged.

Rib: a forged wall or vertical section generally projecting in a direction parallel to the ram stroke.

Rib-and-web forging: one whose basic configuration consists of ribs and webs.

For more information about common forging terminology, visit the Forging Industry Association (FIA) website.

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