This document specifies qualities for steels for seismic-proof improved structural use. It is applicable to steel plates rolled on a reversing mill, wide flats, hot-rolled sections, which are used in the as-rolled condition, with the exception of grade SA440, which is normally produced using quenched and tempered or thermomechanical controlled process and normally intended for welded or bolted structures.

This document covers 5 steel grades and 7 qualities. Grades SA235, SA325, SA345, SA390 and SA440 are covered. Not all grades are available in all qualities, and some qualities have Charpy V‑notch requirements.

The steels specified in this document are applicable to hot-rolled plates, wide flats, and sections with a minimum nominal thickness of 6 mm and a maximum nominal thickness of 150 mm for steel plates, and a maximum nominal thickness of 140 mm for wide flats and hot-rolled sections.

This document does not include the following structural steels, some of which are covered by other International Standards:
— sheet and strip, e.g. ISO 4995 or ISO 4996;
— tubular products. e.g. ISO 12633-1, ISO 12633-2.

NOTE The term "thickness" is considered as "nominal thickness", unless otherwise stated.