wrought iron

Wrought iron is an iron alloy with a very low carbon content (less than 0.05%) in contrast to that of cast iron (2.1% to 4.5%), or 0.25% for low-carbon "mild" steel. Wrought iron is manufactured by heating and melting high-carbon cast iron in an open charcoal or coke hearth or furnace in a process known as puddling. The high temperatures cause the excess carbon to oxidise, the iron being stirred or puddled during the process in order to achieve this. As the carbon content reduces, the melting point of the iron increases, ultimately to a level which is higher than can be achieved by the hearth, hence the wrought iron is never fully molten and many impurities remain.

The primary advantage of wrought iron over cast iron is its malleability – where cast iron is too brittle to bend or shape without breaking, wrought iron is highly malleable, and much easier to bend.