Permanent Mold Casting is a metal casting process that employs reusable molds (“permanent molds”), usually made from metal. The most common process uses gravity to fill the mold, however gas pressure or a vacuum are also used. Common casting metals are aluminum, magnesium, and copper alloys. Other materials include tin, zinc, and lead alloys and iron and steel are also cast in graphite molds.
Permanent mold castings, while not as flexible as sand castings, lower the cost of producing a part. At a production run of 1000 or more parts, permanent mold castings generally produce a lower piece cost part. Of course, the break-even point depends on the complexity of the part. Generally more core complex parts are favored by the use of permanent molds.
Typical parts include gears, wheels, gear housings, pipe fittings, fuel injection housings, and automotive engine pistons.