Q:How many grades are steel bars divided into?

Steel bars can be divided into four grades according to their mechanical properties: steel bar Grade Ⅰ (235/420 grade); steel bar grade Ⅱ (335/455 grade); steel bar grade Ⅲ (400/540) and steel bar grade Ⅳ (500/630). (Based on Chinese national standards）

In addition, steel bars can also be classified by diameter, production manners, rolled shape, or the role of steel bars in structures:

1. Divided by diameter. Steel wire (diameter 3~5mm), thin steel bar (diameter 6~10mm), thick steel bar (diameter greater than 22mm).

2. Divided by the production manners. Hot-rolled, cold-rolled, cold-drawn steel bars, as well as heat-treated steel bars made of grade IV steel bars, have higher strength than the former.

3. Divided by rolled shape. ①Smooth steel bars: Grade I steel bars (Q300 steel bars) are all rolled into a smooth circular section, and the supply form is round, with a diameter not greater than 10mm and a length of 6m~12m. ② Ribbed steel bars: There are three types: spiral, herringbone and crescent. Generally, steel bars grade II and III are rolled into herringbone shapes, and steel bars grade IV  are rolled into spiral and crescent shapes. ③Steel wire (divided into low carbon steel wire and carbon steel wire) and steel strand. ④Cold-rolled and twisted steel bars: after cold rolling and cold twisting.

4. Divided by he role of steel bars in structures. Compression bars, tension bars, erection bars, distributed bars, stirrups , etc.

Time：16/05/2023 08:34:37