It is also known as cold heading. It is a cold working procedure where the material is squeezed into a die and the finished parts assume the shape of the die. This form of forging can be highly automated.
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 steel forgings are most commonly cold-forged. Parts are generally symmetrical and rarely exceed 10KGS. The primary advantage is the material savings achieved through precision shapes that require little finishing. Completely contained impressions and extrusion-type metal flow yield draftless, close-tolerance components. Production rates are very high with exceptional die life. While cold forging usually improves mechanical properties, the improvement is not useful in many common forging applications and economic advantages remain the primary interest. Tool design and manufacture are critical.
According to shape process, they are generally classified to Open die forging, Close die
forging, and Ring forging.