Forging : Open Die Forging
Forging is a metalworking process in which an impact device is used to deliver compressive force to areas of the metal in order to shape it. Forging was originally done manually with a hammer and anvil, however industrial forging machines now use hydraulics, compressed air, or other methods to drive mechanical hammers, or presses, into the surface. Open die forging refers to a drop forging process in which the heated metal is placed into the tools, known as the die and punch. A large, heavy, mechanically-driven hammer is then dropped into the die, forcing the softened metal into the mold cavities of the die and punch. In open die forging, the hammer and die are typically open on the outside edges of the tools, allowing the excess metal to flow freely from the tool once the tool cavities have been filled.