Die Forging and casing have both precision and imprecision, so none of them is more accurate than others. The difference is that the material needs melting during casting, and die forging is not necessary, using the air hammer pressure, the plasticity is strong. Casting is divided into die casting and Sand Casting, die forging is divided into hot forging and cold forging. Forging exerting external force on metal blank to produce plastic deformation, change size, shape and improve performance. It is used to manufacture mechanical parts, workpiece, tool or blank forming process. The microstructure and mechanical properties of the metal can be improved by forging. Generally speaking, the mechanical property of casting is lower than those of the same material.