Angle steel bars are perpendicular elongated steel bars connected together as a wave-like product. There are equal angles and unequal angles. Angle steel bar is a simple sectioned carbon structural steel mostly used in metal products fabrication and construction of workshop. In application, it must has weldability, plasticity deformation performance and high mechanical strength. The raw material to produce angle steel is low-carbon billet. Finished product of angle steel is hot roll formed.