Forging is a kind of pressure of forging machinery for metal blank, make its produce plastic deformation in order to obtain certain mechanical properties, a certain shape and size of forging processing method, forging, forging and stamping) of one of the two part.by forging can eliminate the metal smelting process of as-cast loose defects, such as optimizing the microstructure, at the same time because of the intact metal flow, forging generally better than that of the same material on the mechanical properties of the castings.the important parts with high load and severe working conditions in the related machinery, except for the simple and usable rolled plates, profiles or welding parts, are used for forging.