1.1 This standard covers the requirements for two grades of mild steel (ordinary quality) designated as Fe 310-O (St 32-O) [see IS: 1762 ( Part I )-1974‖ ] and Fe 410-O ( St 42-O ) [see IS : 1762 ( Part I )-1974‖ ]. Steel Fe 310-O (St 32-O) is intended for general engineering purposes and Steel Fe 410-O ( St 42-O) is intended for use in structural work ( see also 0.3 ).
1.1.1 The steel may also be supplied in the copper-bearing quality in which case it shall be designated as Fe 310 Cu-O (St 32-OC) and Fe 410Cu-O (St42-OC).
IS 1977-1975 history
1975IS 1977-1975 Specifications for Structural Steel (General Quality)