In ring rolling, a type of ring The process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. equipment employing (1) Term used to describe a die impression designed to produce more than a single piece at a time. (2) A piece of stock for forging that is cut from bar or billet lengths to provide the exact amount of material needed for a single workpiece. mandrels with a common main roll. Usually used in high volume production of small-diameter rolled rings.