Before
the development of effective steel making processes, wrought iron was the
primary metal used in all industries. Its uses ranged from rivets, wire and chains to warships
and railways. It was the key ingredient in swords, axes and cutlery. Wrought iron
was the most common form of malleable iron, and due to its malleability and
ductility it is perfect for hand work ornamental products. It is strong, workable
and easily welded making it ideal for many different applications requiring hot
or cold working and welding.
Wrought
iron is an iron alloy with a very low carbon content of 0.05 to 0.25%. In
comparison cast iron which contains 2 to 3.4% and pig iron 3.5 to 4.5%. This
low carbon content reduces the brittleness of the metal, making more ductile
and malleable. Wrought iron also contains up to 2% of fibrous
inclusions (slag) by weight. These inclusions give wrought iron a wood like “grain”
that can be seen when stressed or bent to the point of failure. Once considered “commercially pure iron,” wrought
iron is no longer considered pure iron because of modern day specifications of
carbon content of .008% for pure iron. The term “wrought” comes from an archaic past participle of the verb "to work”.
The name of this metal roughly translates to “worked iron”.
The bloomery would
produce wrought iron from iron ore or taking cast and pig iron and melting it
down in a finery forge and puddling furnace and partially removing the slag and
carbon content. A puddling furnace draws hot air over the molten iron without
the oxygen coming in contact with the gases and fumes of the fuel heating the
iron. This reduces the amount of impurities contracted by the molten wrought
iron, and therefore making a higher quality product.
The peak time of
wrought iron production was the 1860’s due to the railways and the development of
ironclad warships, like those used in the American Civil War. The decline came
about as mild steel was more easily produced and advantageous for certain
applications of the metal. Although wrought iron is not commercially produced
like it was in the 1860’s, it is still used today in many different
applications. Ornamental Wrought Iron is used for fences, gates, furniture,
lighting, and many other decorative applications. The ease of working the metal
and the ease of welding the metal make it ideal for ornate decorative pieces.