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