ISO 630-3:2021

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 covers13 grades and 6 qualities. Grades S275, S355, S390, S420, S460 and S500 are covered in AnnexA. Grades SG245, SG290, SG325, SG345, SG365, SG415 and SG460 are covered in AnnexB. 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 3mm and a maximum nominal thickness of 250mm for grades S275N, S355N, S390N, S420N and S460N, a maximum nominal thickness of 150mm for grades S275M, S355M, S390M, S420M, S460M, and S500M, a maximum nominal thickness of 200mm for grades SG245, SG325 and SG415, a maximum nominal thickness of 100mm for grades SG345, SG365 and SG460, and a maximum nominal thickness of 40mm 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 TC17/SC12, Continuous mill flat rolled products;

Tubular products refer to ISO TC5/SC1, Steel tubes.

NOTE1 Lists of standards covered by ISO/TC17/SC12 and ISO/TC5/SC1 are available on the ISO website.

NOTE2 In all parts of ISO630, the term of "thickness" is considered as "nominal thickness", unless otherwise stated.