A lug or ring on the forgingThe process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment. or an impressionA cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging. in the diesThe metal blocks into which forging impressions are machined and from which forgings are produced. of a mechanical upsetterA three-element forging press, with two gripper dies and a forming tool, for flanging or forming relatively deep recesses. to ensure firm clamping of the workpiece in the gripper diesThe lateral or clamping dies used in a mechanical upsetter or forging machine..