Australian Steel Fy and Fu — AS/NZS 3679.1 Yield & Tensile Table
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Complete reference for yield strength (Fy) and tensile strength (Fu) per AS/NZS 3679.1:2016 (sections) and AS/NZS 3678:2016 (plates). Values used in AS 4100 limit state design.
Grade 300 and 300PLUS — Sections
| Thickness | Fy (MPa) | Fu (MPa) |
|---|---|---|
| t ≤ 11 mm | 300 | 430 |
| 11-20 mm | 300 | 430 |
| 20-40 mm | 280 | 430 |
| t > 40 mm | 260 | 410 |
Grade 350 — Sections
| Thickness | Fy (MPa) | Fu (MPa) |
|---|---|---|
| t ≤ 11 mm | 360 | 450 |
| 11-20 mm | 350 | 450 |
| 20-40 mm | 330 | 450 |
| t > 40 mm | 310 | 430 |
Grade 350/400 — Plates
| Grade | t≤12 | 12-20 | 20-40 | >40 |
|---|---|---|---|---|
| 350 Fy | 360 | 340 | 330 | 320 |
| 350 Fu | 480 | 480 | 480 | 450 |
| 400 Fy | 400 | 400 | 380 | 360 |
| 400 Fu | 500 | 500 | 500 | 480 |
Worked Example
Problem: φMsx for 410UB59.7 (Sx=1142×10³ mm³) Grade 300.
Solution: Flange t=11.4 mm > 11 → Fy=280 MPa. φMsx = 0.90 × 280 × 1142×10³ = 287.8×10⁶ Nmm = 288 kNm. Using Fy=300 gives 308 kNm (7% overestimate).
Design Resources
- [[Australian Steel Grades|/reference/australian-steel-grades/]] | [[Australian Steel Properties|/reference/australian-steel-properties/]] | [[Australian Beam Sizes|/reference/au-beam-sizes/]] | [[Australian Bolt Capacity|/reference/australian-bolt-capacity/]] | [[AS 4100 Beam Design|/reference/as4100-beam-design-example/]] | [[All Australian References|/reference/]]
FAQ
What is the design yield for Grade 300 per AS 4100? 300 MPa for t≤11mm, 280 MPa for t>11mm. Use lower value based on thicker element.
What Fu value for bolt bearing calculations? Grade 300: 440 MPa. Grade 350: 480 MPa. Grade 400: 480 MPa per AS 4100 Clause 9.3.2.1.
How does thickness affect capacity? Thicker steel has lower yield due to reduced hot-rolling ratio. Columns with flanges >40 mm may see 10-15% reduction.
Educational Use Only — This reference is for educational and preliminary design purposes only. All structural designs must be independently verified by a licensed Professional Engineer (PE) or Structural Engineer (SE) in accordance with AS 4100:2020 and all applicable Australian Standards. Results are not for construction.