Dimensional accuracy, surface quality, and productivity are high, and a greater degree of deformation can be achieved in a single operation than in any other forging method. Cold Cold forging involves either impression die forging or true closed die forging with lubricant and circular dies at or near room temperature. Carbon and standard alloy steels are most commonly cold-forged. Parts are generally symmetrical and rarely exceed 25 lb. The primary advantage is the material savings achieved through precision shapes that require little finishing.
Production rates are very high with exceptional die life.
While cold forging usually improves mechanical properties, the improvement is not useful in many common applications and economic advantages remain the primary interest. Tool design and manufacture are critical. Warm Warm forging has a number of cost-saving advantages which underscore its increasing use as a manufacturing method. Hot Hot forging is the plastic deformation of metal at a temperature and strain rate such that recrystallization occurs simultaneously with deformation, thus avoiding strain hardening. A form of hot forging is isothermal forging , where materials and dies are heated to the same temperature.