Cast iron

An iron alloy containing about 2 to 4% carbon and 1 to 3% silicon, having a high compressive strength but low tensile strength. Cast iron is manufactured by melting scrap iron or pig iron in a cupola that is in contact with the coal fuel, then casting the molten iron into a mold. A large range of building and decorative items are made of cast iron by pouring the molten metal into sand molds and then machining. It is inexpensive and easy to make. It was made in China by at least the 3rd century BCE; the technique for its production did not reach Europe until medieval times.