The casting material has nothing to do with the mold. The mold is only related to the modeling method. Manual modeling of wooden molds or plastic molds is enough, while mechanical modeling requires metal molds. Only the modeling material is related to the material. Stainless steel can generally be cast in sand molds. The silica content of the raw sand must be greater than 98%, and the silica content of the raw sand for copper parts must be greater than 85%. The technology can choose sodium silicate sand, resin sand, stainless steel brushed with zircon powder paint, and copper castings can use ordinary paint.