Wrought Iron is an iron alloy with a very low carbon (less than 0.08%) content in contrast to cast iron (2.1% to 4%) and has fibrous inclusions known as slag up to 2% by weight. It is a semi-fused mass of iron with slag inclusions which gives it a “grain” resembling wood, that is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile, corrosion resistant and easily welded.
Before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron. A modest amount of wrought iron was used as a raw material for refining into steel, which was used mainly to produce swords, cutlery, chisels, axes and other edged tools as well as springs and files. The demand for wrought iron reached its peak in the 1860s with the adaptation of ironclad warships and railways, but then declined as mild steel quality problems such as brittleness were solved and it became inexpensive and widely available.
Many items, before the came to be made of mild steel, were produced from wrought iron, including rivets, nails, wire, chains, rails, railway couplings, water and stream pipes, nuts, bolts, horse shoes, handrails, wagon tires, straps for timber roof trusses and ornamental ironwork.