Construction steel is generally divided into structural steel and rebar for reinforced concrete structures. Structural steel primarily includes ordinary carbon structural steel and low-alloy structural steel. Varieties include sections, steel pipes, and rebar. Sections include angles, I-beams, and channels.
Rebar for reinforced concrete structures can be categorized by processing method: hot-rolled steel, heat-treated steel, cold-drawn steel, cold-drawn low-carbon steel wire, and stranded steel pipe; by surface shape: plain steel and threaded steel; and by steel type: low-carbon steel, medium-carbon steel, high-carbon steel, and alloy steel. Rebar in my country is classified by strength into five grades: I, II, III, IV, and V.