Mild steel consists of iron alloyed with less than 0.3 percent carbon, most commonly between 0.1 to 0.25 percent. The building industry frequently uses mild steel in construction because of its ductility and malleability.
Girders, nuts, bolts, and screws often consist of mild steel, according to the UK Technology Education Centre. Mild steel has also replaced wrought iron for railings and decorative gates.
Ductility refers to the ability of a material to resist fracture or breakage despite changes in shape caused by bending or elongation, according to BusinessDictionary.com.
Malleability refers to the ability of a material to resist cracking despite being twisted or bent. The malleability of mild steel also allows it to be rolled or beaten into thin sheets, according to the Business Dictionary.