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

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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.