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.

The hot-rolled ribbed steel bar is divided into three grades: HRB335 (the old grade is 20MnSi), grade three HRB400 (the old grade is 20MnSiV, 20MnSiNb, 20Mnti), and grade four HRB500.