Structural steel standards are typically based on the Australian/New Zealand Joint Standards (AS/NZS) developed by Committee BD-023, Structural Steel.
1. Hot-Rolled Steel Plates, Floor Plates, and Thick Plates (AS/NZS 3678:2016)
This standard specifies the requirements for hot-rolled structural steel plates, floor plates, and thick plates used in structural and general engineering applications.
Scope:
Applies to mechanically tested steel, analysis-only steel, and weathering steel that has undergone mechanical testing.
Applications:
Suitable for welding in accordance with AS/NZS 1554 (Parts 1, 2, 5, 7) and for assembly using fasteners compliant with AS 3990, AS 4100, AS/NZS 4600, AS 5100.6, and NZS 3404.1.
Grade Designations:
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AS/NZS 3678-250 (mechanically tested steel)
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AS/NZS 3678-WR350 (weathering steel)
Suffixes Z, L, Y, FG indicate special properties such as ductility, impact resistance, or fine-grained structure.
Mechanical Requirements (Grade 250):
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Minimum Yield Strength: 250 MPa
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Minimum Tensile Strength: 410 MPa
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Minimum Elongation: 24%
2. Hot-Rolled Steel Bars and Sections (AS/NZS 3679.1:2016)
This standard covers the requirements for the manufacture and supply of hot-rolled structural steel bars and sections (round, square, U, H, etc.).
Grade Designation Example:
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AS/NZS 3679.1-350 → Minimum yield strength 350 MPa
Suffix meanings:
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L0, L15: Low-temperature impact resistance
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S0: Seismic grade
Mechanical Requirements (Grade 350):
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Minimum Yield Strength: 340–360 MPa
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Minimum Tensile Strength: 480 MPa
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Minimum Elongation: 20–25%
Impact Test:
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Grades 350L0 and 350S0: Average absorbed energy 27 J at 0°C
3. Cold-Formed Structural Steel Hollow Sections (AS/NZS 1163:2016)
This standard specifies requirements for the manufacture and supply of longitudinally welded cold-formed structural steel hollow sections.
Grade Designation Example:
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AS/NZS 1163–C350
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“C” stands for cold-formed
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“350” indicates minimum yield strength of 350 MPa
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Chemical Composition (C350):
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C ≤ 0.20%
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Si ≤ 0.50%
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Mn ≤ 1.60%
Mechanical Requirements (Grade C350):
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Minimum Yield Strength: 350 MPa
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Minimum Tensile Strength: 430 MPa
4. Welded I-Sections (AS/NZS 3679.2:2016)
This standard specifies the requirements for welded I-sections manufactured from plate steel.
Feed Material:
Must be hot-rolled structural steel plate compliant with AS/NZS 3678.
Welding Requirements:
Must conform to AS/NZS 1554.1, Category SP.
Testing:
A web-to-flange tensile test must be performed to ensure weld strength.
