This document specifies requirements for flat and long products of hot-rolled weldable fine-grain structural steels in the as-rolled (for SG grades only), normalized/normalized rolled and thermomechanical processed delivery conditions. It applies to steel plates rolled on a reversing mill, wide flats, hot-rolled sections and bars, which are intended for use in heavily loaded parts of welded or bolted structures.

This document covers°°13 grades and 6 qualities. Grades S275, S355, S390, S420, S460 and S500 are covered in Annex°°A. Grades SG245, SG290, SG325, SG345, SG365, SG415 and SG460 are covered in Annex°°B. 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, sections and bars with a minimum nominal thickness of 3°°mm and a maximum nominal thickness of 250°°mm for grades S275N, S355N, S390N, S420N and S460N, a maximum nominal thickness of 150°°mm for grades S275M, S355M, S390M, S420M, S460M, and S500M, a maximum nominal thickness of 200°°mm for grades SG245, SG325 and SG415, a maximum nominal thickness of 100°°mm for grades SG345, SG365 and SG460, and a maximum nominal thickness of 40°°mm for grade SG290.

This document does not include the following structural steels, some 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.

NOTE°°1°°°°°° Lists of standards covered by ISO/TC°°17/SC°°12 and ISO/TC°°5/SC°°1 are available on the ISO website.

NOTE°°2°°°°°° In all parts of ISO°°630, the term of "thickness" is considered as "nominal thickness", unless otherwise stated.