What is a foundry?

   A foundry is a building or group of buildings in which pig iron, aluminum, brass, bronze, steel, or other metal is melted and cast into shape. The most important installations in a modern foundry are the furnace for melting the metal and the patterns and molds for casting it into various shapes. Iron is more commonly used than steel for castings because it does not warp or crack when near heat. Also iron melts at a lower temperature than steel, and it is hard and wear resistant. Iron for casting is melted in several kinds of furnaces. The most important is the cupola, a furnace in which steel scrap, iron scrap, pig iron, and coke are used. The molds, or patterns, for casting must be accurate and must allow for the shrinkage of metal. There is much variety both in the shapes of molds and the materials for making them, although molds and cores are usually made of sand.