Stainless steel precision casting or investment casting, silica sol process. It is a casting process with less cutting or no cutting. It is an excellent technology in the foundry industry. It is widely used. It is not only suitable for casting of various types and alloys, but also the dimensional accuracy of the produced castings, The surface quality is higher than other casting methods, and even castings that are difficult to cast by other casting methods, high temperature resistance, and difficult to process can be cast by investment precision casting.