AS/NZS 3679.1: the hot-rolled structural steel standard (Grade 300)
AS/NZS 3679.1:2016 specifies hot-rolled structural steel bars and sections. Grade 300 is the default supply grade for UB, UC, and PFC sections.
Ask Chalkline about this →AS/NZS 3679.1:2016, Structural steel, Part 1: Hot-rolled bars and sections is the joint Australian/New Zealand Standard that sets production and supply requirements for hot-rolled structural steel sections: universal beams (UB), universal columns (UC), parallel flange channels (PFC), and angles (verified 2026-06-11, Standards Australia store).
The 2016 edition is current, superseding AS/NZS 3679.1:2010.
The grades
Two strength grades matter in practice:
| Grade | Nominal min. yield strength | Common use |
|---|---|---|
| 300 | 300 MPa | Default for all UB, UC, PFC supply in Australia |
| 350 | 350 MPa | Heavier commercial or specifier-selected sections |
Grade 300 is what you get unless the drawings call for Grade 350. Mill certificates from suppliers such as InfraBuild and Liberty reference the standard and grade directly.
Part 1 vs Part 2
AS/NZS 3679.1 (Part 1) covers hot-rolled open sections and bars. AS/NZS 3679.2:2016 (Part 2) covers welded I sections, which are fabricated by welding plates rather than hot-rolling. Hollow sections (SHS, RHS, CHS) fall under a separate standard, AS/NZS 1163.
Relationship to AS 4100
AS/NZS 3679.1 governs material supply: chemical composition, dimensional tolerances, and mechanical properties. AS 4100 governs structural design: how an engineer sizes a member, checks buckling, and designs connections. Both standards are always in play on any structural steel job.
For a builder
- Every UB or UC on a set of structural drawings was supplied to AS/NZS 3679.1. The grade (300 or 350) is on the mill certificate.
- Do not substitute a section without the engineer’s mark-up. Even if the new section is nominally the same grade, AS 4100 design may have relied on a specific section’s geometry.
- Keep mill certificates on file. They are evidence that material supplied matches the spec called up on the drawings.
Category: Standard / structural steel.
Related
See also
References
- AS/NZS 3679.1:2016, Structural steel Part 1: Hot-rolled bars and sections, Standards Australia (verified 2026-06-11)
- Australian Steel Institute: AS/NZS 3679.1:2016 entry (verified 2026-06-11)
- Building CodeHub NZ: AS/NZS 3679.1:2016 (verified 2026-06-11)
Last updated: 2026-06-11. Verified: 2026-06-11. Quarterly review for currency.