Composition, grade and variety of steel bars

1.According to chemical composition 

Carbon steel (iron, carbon, silicon, manganese, sulfur, phosphorus and other elements)

Low carbon steel (carbon content <0.25%)

Medium carbon steel (carbon content 0.25~0.6%)

High carbon steel (carbon content 0.6~1.4%)

Ordinary low alloy steel (plus silicon, manganese, titanium, vanadium, chromium, etc.)

Silicon series, silicon vanadium series, silicon titanium series, silicon manganese series, silicon chromium series

2. According to processing method

Hot-rolled steel bars: hot-rolled smooth steel bars HPB235, hot-rolled ribbed steel bars HRB335, HRB400, waste heat-treated steel bars RRB400.

HPB235 grade steel bars: plain round steel bars, nominal diameter range is 8~20mm, recommended diameters are 8, 10, 12, 16, 20mm. In actual projects, they are only used as stress-bearing main bars for slabs, foundations and beams and columns with small loads. stirrups and other structural steel bars.

HRB335 grade steel bars: crescent-shaped steel bars, nominal diameter range is 6~50mm, recommended diameters are 6, 8, 10, 12, 16, 20, 25, 32, 40 and 50mm. It is an auxiliary steel bar for concrete structures and is also mainly used as the stress-bearing main bar in structural components in actual projects.

HRB400 grade steel bar: Crescent pattern steel bar, the nominal diameter range and recommended diameter are the same as HRB335 steel bar. It is the dominant steel bar in concrete structures and is mainly used as the stress-bearing main bar in structural components in actual projects.

RRB400 grade steel bars: crescent pattern steel bars, nominal diameter range is 8~40mm, recommended diameters are 8, 10, 12, 16, 20, 25, 32 and 40mm. Although its strength is high, its fatigue performance, cold bending performance and weldability are poor, and its application is subject to certain limitations.

Cold-drawn steel bars: made from hot-rolled steel bars that are mechanically stretched at room temperature.

Hard-drawn steel bars: At normal temperature, hot-rolled smooth round steel bars are forcibly drawn through a tapered hole smaller than the diameter of the steel bar in a carbide drawing die.

Cold-rolled steel bar: A smooth round ordinary low-carbon or low-alloy steel bar that is rolled at room temperature to make its diameter smaller and its surface ribbed.

Heat-treated steel bars: HRB400 and RRB400 steel bars are made by heating, quenching and tempering.

Quenching: Strength increases and plasticity decreases.

Tempering: Eliminates the internal force generated by quenching and improves plasticity and toughness without reducing strength.

Steel wire: Carbon steel wire: High carbon killed steel is made through multiple cold drawing, stress relief, correction and tempering treatments.

Scored steel wire: Score the surface of the steel wire to enhance its bond with concrete.

Steel strand: Multiple steel wires of the same diameter twisted together in a spiral.

Cold drawn low carbon steel wire: cold drawn from low carbon steel.