Pig iron is remelted and cast into various objects such as engine blocks, stoves and so on. It is then called cast iron. The presence of the impurities makes cast iron brittle and difficult to weld. It is used only in appliances which are not subject to great strain.
The main types of cast iron are:
1. Grey cast iron.
2. White cast iron.
3. Malleable cast iron.
4. Ductile cast iron