This part of ISO 630 specifies qualities for steels with improved atmospheric corrosion resistance for general structural use. It applies to steel plates rolled on a reversing mill, wide flats, hot-rolled sections and bars, which are used in the usual delivery conditions as given in 6.3, and normally intended for welded or bolted structures. This part of ISO 630 covers nine (9) grades and four (4) qualities. Grades S235 and S355 are covered in Annex A. Grades SG245, SG345, SG365, SG400, SG460, SG500, and SG700 are covered in Annex B. Not all grades are available in all qualities, and some qualities have Charpy V-notch requirements. This part of ISO 630 does not include the following structural steels, certain of which are covered by other International Standards: — sheet and strip – refer to ISO TC 17/SC 12 “Continuous mill flat rolled products”; — tubular products – refer to ISO TC 5/SC 1 “Steel tubes”.