There are two common methods for classifying reinforcing bars: one is based on geometric shape, categorizing or typing them according to the cross-sectional shape of the transverse ribs and the spacing between them, such as the British Standard (BS4449) which divides reinforcing bars into Type I and Type II. This method primarily reflects the gripping performance of reinforcing bars. The other is performance-based classification (grade), for instance, China's standard (GB1499) categorizes reinforcing bars into three grades based on strength levels (yield point/tensile strength); Japan's Industrial Standard (JISG3112) divides them into five types based on comprehensive properties; and the British Standard (BS4461) also specifies several grades for performance testing of reinforcing bars. Additionally, reinforcing bars can be classified by their applications, such as ordinary reinforcing bars for reinforced concrete and heat-treated reinforcing bars for reinforced concrete, etc.

Reinforcing ribbed hot-rolled steel bars used in concrete and reinforced concrete in China are standardized by national standards, with the grade composed of the HRB prefix and the minimum yield point value. H, R, and B stand for the initials of Hot Rolled, Ribbed, and Bars in English. The reinforcing ribbed hot-rolled steel bars are categorized into three grades: HRB335 (old grade 20MnSi), HRB400 (old grades 20MnSiV, 20MnSiNb, 20MnSiTi), and HRB500.