Steel bar (also called "granular steel") is a kind of steel strip and a building material. For example, in reinforced concrete, it is used to support the skeleton of the structure. Include round steel, ribbed steel bar and torsion steel bar. There are many kinds of steel bars, which are usually classified according to chemical composition, production technology, rolling shape, supply form, diameter and application in structure. Steel bars mainly bear tensile stress in concrete. Deformed steel bars have great bonding ability with concrete due to the action of ribs, so they can better withstand the action of external forces. Steel bars are widely used in various building structures, especially large, heavy, light thin-walled and high-rise building structures.