What's the Difference Between Iron & Cast Iron?

Iron

• Regular, or wrought, iron is the original way of constructing objects out of this heavy material. The modern process involves smelting the iron ore for a long period of time at relatively low heat to remove the impurities from the ore. The iron is then hammered into the desired shape, a process that also removes impurities in the metal.

Cast Iron

• Cast iron goes through a relatively similar process. It is smelted as regular iron but for shorter duration and at higher temperature. When molten, it is poured into casts to form the required shape. As cast iron is not hammered nor treated for long, it is not as pure as wrought iron.

Properties

• Because wrought iron is so pure, it can withstand severe weather conditions without rusting or corroding. Cast iron will rust and break if struck with a hammer. For this reason cast iron is sometimes called brittle iron.

Applications

• In broad terms, both irons are used for outdoor metalworking. Manhole covers and street drains are made form cast iron as the mould can be used over and over to give regular shapes. Wrought iron, on the other hand, is used for garden gates and similar objects that cannot be cast due to irregular patterns.