Mild steel is popular for mechanical engineering and general purpose fabrication because it is malleable, meaning that it bends, rolls and welds very well. Its combination of strength and malleability makes it an excellent choice of metal for the construction of panels, frames, fencing and other applications where it will not be subjected to high stress. The category of mild steel includes various grades of structural steel, some of which are used in the most demanding environments such as offshore structures, power plants, mining and earth-moving equipment.