Silica sol castings are mainly used for products with high corrosion resistance and precision dimensions. The Silica sol castings gives the possibilities to eliminate the need for secondary machining after casting. The alloys typical produces is carbon steel and stainless steel castings. Silica sol casting is the casting process that uses silica sol (silica solution) as the binder material to build the casting mold. The metal castings produced by silica sol casting have fine surfaces and high accuracy and the general dimensional tolerance grade is up to CT4 - CT6. And this process is the main investment casting process of RMC for stainless steel castings and alloy steel castings. Silica sol is mainly used in precision casting, due to its relatively high production cost, but gives very fine precise dimensions, good surface finish, and overall very good quality.