PUDDLE IRON

'Puddle iron' is a type of wrought iron. Its production process was invented at the end the eighteenth century, following an increase in the need for wrought iron. It is produced in a puddling furnace. The process results with an iron that contains a slightly increased carbon content compared to wrought iron. This provides it with a higher tensile strength. The puddling furnace also allows a better control of the chemical composition of the iron. The Eiffel Tower was built with puddle iron for a large part of its structure. Other standing structures such as bridges also used puddle iron. This is a very pure form of iron, used mainly in construction.