Precision casting is one of the methods of casting. Precision casting is a special casting method compared to traditional casting processes. It achieves relatively accurate shape and high casting accuracy. The more common practice is to first design and manufacture the mold according to the product requirements (there may be a very small amount or leave no margin), cast the wax by casting method, and obtain the original wax mold; repeat the coating and sanding on the wax mold. Process, hardening shell and drying; then melting the internal wax mold, for dewaxing, obtaining the cavity; roasting shell to obtain sufficient strength and gas permeability; pouring the required metal material; sanding after shelling In order to obtain a high-precision finished product. Heat treatment and cold working according to product requirements.