It is a highly refined iron with a small amount of slag forged out into fibres. The chemical analysis of the metal shows as much as 99 percent of iron. The slag characteristic of wrought iron is useful in black smithing operations and gives the material its peculier fibrous structure.
The non-corrosive slag constituent causes wrought iron to be resistant to progressive corrosion. Moreover, the presence of slag produces a structure which diminishes the effect of fatigue caused by shocks and vibrations.
The wrought iron is a tough malleable and ductile material. It can not stand sudden and excessive shocks. It can not be melted, but at a white heat, it becomes soft enough to take any shape under the hammer, i.e., it can be forged.
It can be easily welded. It rusts more quickly than cast iron but stands in salt water better. It can neither be hardened nor tempered. The melting point of wrought iron is about 1530°C.
It is used for bolts and nuts, chains, crane hooks, railway couplings, pipes and pipe fittings, plates, sheets, bars and boiler tubes, water and steam pipes.