For fine grain steel structural hollow sections the steel designation consists of:
– the number of the European Standard;
– the letter S for structural steel;
– the indication of the minimum specified yield strength for thicknesses ≤ 16 mm expressed in w MPa (1 MPa = 1 N/mm2)
– the letter N to indicate normalized or normalized rolled feedstock material;
– the letter L for the qualities with specified impact properties at -50°C;
– the letter H to indicate hollow section.