Forging is a processing method that uses forging machinery to exert pressure on metal blank to make it produce plastic deformation to obtain forgings with certain mechanical properties, certain shapes and sizes. Forging (forging and stamping) is one of the two major components. Forging can eliminate as cast porosity and other defects produced in the smelting process of metal, optimize the microstructure. At the same time, due to the preservation of complete metal streamline, the mechanical properties of forgings are generally superior to castings of the same material. For important parts with high load and severe working conditions in related machinery, forgings are mostly used, except for simple rolled plates, profiles or weldments.