cast iron

cast iron

noun

: a very hard type of metal that is made into different shapes by being melted and poured into special containers (called casts or molds)

Full Definition of CAST IRON

:  a commercial alloy of iron, carbon, and silicon that is cast in a mold and is hard, brittle, nonmalleable, and incapable of being hammer-welded but more easily fusible than steel

Examples of CAST IRON

1. The fence is made of cast iron.

First Known Use of CAST IRON

1664

cast iron

noun    (Concise Encyclopedia)

Alloy of iron that contains 2–4% carbon, along with silicon, manganese, and impurities. It is made by reducing iron ore in a blast furnace (cast iron is chemically the same as blast-furnace iron) and casting the liquid iron into ingots called pigs. Pig iron is remelted, along with scrap and alloying elements, in cupola furnaces and recast into molds for a variety of products. In the 18th–19th centuries, cast iron was a cheaper engineering material than wrought iron (not requiring intensive refining and hammering). It is more brittle and lacks tensile strength. Its compressive (load-bearing) strength made it the first important structural metal. In the 20th century, steel replaced it as a construction material, but cast iron still has industrial applications in automobile engine blocks, agricultural and machine parts, pipes, hollowware, stoves, and furnaces. Most cast iron is either so-called gray iron or white iron, the colours shown by fracture; gray iron contains more silicon and is less hard and more machinable than white iron. Both are brittle, but malleable cast iron (produced by prolonged heat-treating), first made in 18th-century France, was developed into an industrial product in the U.S. Cast iron that is ductile as cast was invented in 1948. The latter now constitutes a major family of metals, widely used for gears, dies, automobile crankshafts, and many other machine parts.