Rebar or reinforcement is steel that is used in concrete to compensate for its tensile strength. Rebars are produced with different standards and in each standard there is a specific classification according to the mechanical properties of steels. Rebars are used to strengthen buildings, bridges, dams, etc., rebars are connected by wire. In Iran, most of the reinforcement steels comply with the Russian standard.

Types of rebars in terms of production standards (according to Russian standards) and their appearance:

Rebar A1 (S240): (simple)
Rebar A2 (S340): (plain and ribbed)
Rebar A3 (S400): (Ribbed)
Rebar A4 (S500): (Ribbed)