Most people often assume that wrought iron and cast are one in the same. However, there is quite a difference between these two types of metal.
Wrought iron is a soft material produced from semi-fused pure iron surrounded by slag. It contains less than 0.1 percent carbon and 1-2 percent slag.
In contemporary usage, wrought iron is metal that is “worked”, often on an anvil. Using the skills of a blacksmith, the metal is heated in a forge and hammered to shape. A metalsmith can either forge the metal by hand over an anvil or by using a modern power hammer.
However, wrought iron has come to refer to ornamental metal assemblies which can often be a combination of cast and forged components. Be very careful when specifying wrought iron that both the designer and fabricator are using the same definitions.
Wrought iron also is a term used to refer to an alloy that is no longer produced but was preferred by blacksmiths when forging.
While genuine wrought iron is not readily available for forge work, pure iron is, and is a material often used to replace wrought iron in restoration work. Otherwise, genuine wrought iron is often salvaged from old bridges and structures.
Cast iron is a generic term that refers to a range of iron alloys. It is an alloy containing 2%-4% carbon, and smaller amounts of silicon and manganese. Cast iron or aluminum is metalwork produced in a foundry. At the foundry, metal ingots are melted in furnaces and the molten metal is poured into molds. Castings permit much more detail in the elements than you might find in a forging.
Cast irons tend to be brittle, except for malleable cast irons. Malleable iron is cast iron which goes through an annealing heat treatment which makes it weldable, less brittle, and formable. Making it ideal for railings. For more information contact us.