There shall be nine grades of steel as given in Tables 1 and 2. For grades E 250 to E 410, there shall be four sub-qualities (A, BR, B0 and C) and for grades E 450 to E 650, there shall be two sub-qualities (A and BR). Sub-qualities A, BR, B0 and C indicate requirement of impact test and mode of de-oxidation as indicated below:
- A : Impact test not required, semi-killed/killed
- BR : Impact test optional; if required at room temperature; semi-killed/killed
- B0 : Impact test mandatory at 0°C, semi-killed/ killed
- C : Impact test mandatory at –20°C, killed
While placing the order, the steel should be designated by ‘Grade Designation’ and ‘quality’ (see Table 1 and Table 2).