Angle Iron is a L shaped steel bar. One angle is perpendicular to the other. This forms an inside angle as well as an outside angle. It is made of mild steel and is suitable for a wide variety of applications. Angle bars are used to offer a strengthened support to structures that otherwise would not be able to endure the pressure placed on them. They are also used to reinforce edges on surfaces to prevent damage or erosion due to weathering. In the simplest sense, angle bars are used to protect any edges and corners that are required to hold their shape.