It is obtained by re-melting pig iron with coke and lime stone in a furnace known as Cupola. It is primarily an alloy of iron and carbon. The carbon contents in cast iron varies from 2 to 4 percent.
It also contains small amounts of silicon, manganese, phosphorus and sulphur and certain amount of alloying elements, e.g, nickel chromium, molybedenum, copper and vanadium.
Since the cast iron is a brittle material therefore it can not be used in those parts which are subjected to shocks.
The properties of cast iron which makes it valuable material for engineering purposes are its low cost, good casting characteristics, high compressive strength, wear resistant and excellent machinability.
The compressive strength of cast iron is much greater than tensile strength. The varieties of in common cast iron use are.