Ordinary carbon structural steel is also called ordinary carbon steel. The carbon content is 0.06-0.22%, with less than 0.25% being the most commonly used. Belonging to low carbon steel, each metal grade represents the lowest yield point of the steel when the thickness is less than 16mm.

Threaded steel rebar is a common name for hot-rolled ribbed steel bars. The grade of ordinary hot-rolled steel bar consists of HRB and the minimum yield point of the grade. H, R, and B are the first letters of the three words, Hot rolled, Ribbed, and Bars, respectively.

In HRB600, the “H” denotes hot-rolled, the ‘R’ denotes ribbed, the “B” denotes reinforcing bar, and 600 indicates a standard yield strength of 600 MPa. Compared to HRB400 grade steel bars, HRB600 grade steel bars offer 39% higher strength. Under identical load-bearing conditions, this significantly reduces the required reinforcement ratio and decreases steel consumption.

HRB500 rebar stands as one of the core representatives of high-strength seismic-resistant steel bars in China's construction engineering sector. Its performance metrics, application scenarios, and technical requirements strictly adhere to national standards. Primarily used in building structures subjected to significant loads and demanding the highest levels of structural safety and seismic performance, it serves as the “skeletal material” for critical projects such as super high-rise buildings, long-span bridges, and heavy-duty industrial plants.

HRB400 rebar is the mainstream variety of hot-rolled ribbed bars. “HRB” stands for “Hot-Rolled Ribbed Bars,” while “400” indicates its standard yield strength is no less than 400 MPa. As the primary load-bearing rebar currently used in construction projects, it boasts the highest consumption and widest application.

HPB300 rebar is the core variety of hot-rolled plain bars. “HPB” stands for “Hot-Rolled Plain Bars,” while “300” indicates its standard yield strength is no less than 300 MPa. As one of the most widely used fundamental reinforcing bars in construction projects, it is extensively applied in load-bearing, structural, and stirrup scenarios within concrete structures due to its ease of processing and moderate cost.