Permanent Mold casting, also refered to Gravity die casting is mainly used for nonferrous metals and alloys. Instead of using sand as the mold material, the mold (or die) is usually iron, steel, or graphite, and is cooled by water channels or by air jets on the outer surfaces. Cavity surfaces in metal dies are coated with a thin layer of heat-resistant material. The mold or die design is usually in two halves, although many multiple-part molds are in use, with loose sand or metal cores to form "undercut" surfaces.
Permanent mold castings, while not as flexible as sand castings in allowing the use of different patterns (different part designs), lower the cost of producing a part. At a production run of 1000 or more parts, we use permanent mold castings to produce a lower piece cost part. Typical part sizes range from 50 g to 50 kg (1.5 ounces to 150 lb). Typical materials used are small and medium sized parts made from aluminum, brass and their alloys. Typical parts include gears, splines, wheels, gear housings, pipefittings, fuel injection housings.And at present, More complex parts being favored by the use of permanent molds by Sinco Machine.