Investment casting is also called lost wax casting, including waxing, waxing, grouping, dipping, melting wax, casting molten metal and post-treatment. Lost wax casting is a wax mold in which a part is to be cast with wax, and then the wax mold is coated with mud, which is a mud mold. After the mud mold is dried, the internal wax mold is melted by placing it in hot water. The mud mold from which the wax mold has been melted is taken out and baked into a ceramic mold. Once roasted. In the general clay mold, the pouring port is left, and the molten metal is poured from the pouring port. After cooling, the required parts are prepared.