Forging Terms and Definitions: R-Z

From Rough Machining to Wide tolerance
Courtesy of Forging Industry Association

Rough machining: an initial machining operation that leaves adequate stock for subsequent finish machining.

Saddle/mandrel forging: rolling and forging a pierced disc over a mandrel to yield a seamless ring or tube.

Slab: a flat-shaped semifinished, rolled metal ingot with a width not less than 10 in. and a cross-sectional area not less than 16 sq. in.

Standard tolerance: an established tolerance for a certain class of product; preferred over "commercial" or "published" tolerance.

Straightening: a finishing operation for correcting misalignment in a forging or between different sections of a forging.

Structural integrity: inherent microstructural soundness of forgings as a result of achieving 100% density, uniform metallurgical structure and grain size, as well as the absence of porosity, segregation, large inclusions and other non-forged part defects.

Swaging: reducing the size of forging stock; alternately, forging in semicontoured dies to lengthen a blank.

Target machining: incorporating a "target" (benchmark or gage point) on a forging to facilitate machining; coined locating surfaces and drilled centers are commonly used.

Trimming: performed hot or cold, the mechanical shearing of flash or excess material from a forging by use of a trimmer in a trim press.

Upset forging: one made by upset of an appropriate length of bar, billet or bloom; working metal to increase the cross-sectional area of a portion or all of the stock.

Upsetter (forging machine): a machine with horizontal action used to produce upset forgings.

Warm forging: forging of steel at temperatures ranging from about 1000 degrees F to just below the normal hot working range of 1900 to 2300 degrees F.

Web: a relatively flat, thin portion of a forging - generally parallel to the forging plane - that connects ribs and bosses.

Wide tolerance: any special tolerance wider than "standard".

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