Hot-rolled steel bars are finished steel bars that are hot-rolled and naturally cooled. They are made of low-carbon steel and ordinary alloy steel pressed at high temperatures. They are mainly used for reinforcement of reinforced concrete and prestressed concrete structures. They are one of the most widely used steel varieties in civil engineering.

Hot-rolled steel bars are steel bars with a diameter of 6.5 to 9 mm, most of which are rolled into wire rods; those with a diameter of 10 to 40 mm are generally straight bars 6 to 12 meters long. Hot-rolled steel bars should have a certain strength, namely the yield point and tensile strength, which is the main basis for structural design. They are divided into hot-rolled plain round steel bars and hot-rolled ribbed steel bars. Hot-rolled steel bars are soft steel, and necking will occur when they break, with a large elongation.

Hot-rolled steel bars should have a certain strength, namely the yield point and tensile strength, which is the main basis for structural design. At the same time, in order to meet the requirements of structural deformation, absorption of seismic energy, and processing and forming, hot-rolled steel bars should also have good plasticity, toughness, weldability, and bonding properties between steel bars and concrete.

HPB300 (grade I) is a common steel bar with a diameter of 6-12 mm. It is commonly used to make stirrups, wall reinforcement, etc.

HRB335 (grade II) is a threaded steel bar with a diameter of 12-25 mm. It is commonly used for beams, columns, and shear walls in large and medium-sized concrete structures such as bridges, dams, and houses. HRB400 (grade III) is similar to HRB 335, but has higher strength and a higher price. It is commonly used in special buildings such as villas.