Australian Universal Beam Sizes — AS/NZS 3679.1 UB Table
Australian standard universal beam (UB) sections are hot-rolled to AS/NZS 3679.1:2016 and designed per AS 4100:2020. This reference provides dimensions, masses, and section properties for the most common Australian UB sizes.
Standard steel grade is Grade 300 (fy = 300 MPa) per AS/NZS 3679.1. Grade 300PLUS offers guaranteed weldability and Charpy V-notch toughness for demanding applications.
Common UB Section Properties
| Designation | Mass (kg/m) | d (mm) | bf (mm) | tw (mm) | tf (mm) | Ix (×10⁶ mm⁴) | Zx (×10³ mm³) | rx (mm) |
|---|---|---|---|---|---|---|---|---|
| 250UB25.7 | 25.7 | 254 | 124 | 5.0 | 8.0 | 35.4 | 278 | 95.7 |
| 250UB31.4 | 31.4 | 256 | 126 | 5.6 | 9.2 | 44.1 | 344 | 96.6 |
| 250UB37.3 | 37.3 | 258 | 128 | 6.4 | 10.9 | 52.8 | 410 | 97.5 |
| 310UB32.0 | 32.0 | 298 | 150 | 4.8 | 8.0 | 49.4 | 332 | 108 |
| 310UB40.4 | 40.4 | 300 | 152 | 5.6 | 9.5 | 63.7 | 424 | 109 |
| 310UB46.2 | 46.2 | 302 | 154 | 6.4 | 11.0 | 74.5 | 493 | 110 |
| 360UB44.7 | 44.7 | 346 | 170 | 5.8 | 9.8 | 88.3 | 510 | 122 |
| 360UB50.7 | 50.7 | 348 | 172 | 6.4 | 11.0 | 101 | 582 | 123 |
| 360UB56.7 | 56.7 | 350 | 174 | 7.0 | 12.0 | 113 | 645 | 124 |
| 410UB53.7 | 53.7 | 396 | 190 | 6.1 | 10.2 | 128 | 647 | 139 |
| 410UB59.7 | 59.7 | 398 | 192 | 6.7 | 11.4 | 143 | 720 | 140 |
| 410UB69.0 | 69.0 | 400 | 194 | 7.5 | 13.0 | 165 | 826 | 141 |
| 530UB82.0 | 82.0 | 512 | 210 | 7.6 | 12.4 | 260 | 1016 | 164 |
| 530UB92.4 | 92.4 | 518 | 212 | 8.4 | 14.2 | 295 | 1138 | 165 |
| 610UB101 | 101 | 590 | 228 | 7.7 | 13.0 | 363 | 1230 | 186 |
| 610UB113 | 113 | 594 | 230 | 8.5 | 14.6 | 409 | 1378 | 187 |
| 610UB125 | 125 | 598 | 232 | 9.3 | 16.2 | 454 | 1518 | 188 |
| 700UB133 | 133 | 678 | 250 | 9.3 | 15.0 | 531 | 1566 | 203 |
| 700UB150 | 150 | 682 | 252 | 10.2 | 16.6 | 598 | 1754 | 204 |
| 700UB173 | 173 | 688 | 254 | 11.4 | 18.6 | 694 | 2018 | 205 |
Grade 300 Mechanical Properties
| Property | Value |
|---|---|
| Yield strength (flange ≤ 11 mm) | fy = 300 MPa |
| Yield strength (flange > 11 mm) | fy = 280 MPa |
| Tensile strength | fu = 430 MPa |
| Minimum elongation | 22% |
| Design capacity factor (phi) | 0.90 (AS 4100 Table 3.4) |
Worked Example: Beam Section Selection
Problem: Select a UB section for a simply supported beam spanning 8.0 m with a design uniformly distributed load of w* = 25 kN/m (factored). Use Grade 300 steel.
Solution:
Maximum bending moment: M* = w*L²/8 = 25 × 8.0²/8 = 200 kNm
Required section modulus: Zx ≥ M*/(phi × fy) = 200 × 10⁶ / (0.90 × 300) = 740,741 mm³ = 741 × 10³ mm³
From the table: 410UB59.7 has Zx = 720 × 10³ mm³ (insufficient), 410UB69.0 has Zx = 826 × 10³ mm³ (sufficient)
Check self-weight: 410UB69.0 = 69.0 kg/m × 9.81/1000 = 0.68 kN/m. Add to load: w* = 25 + 1.2 × 0.68 = 25.82 kN/m. M* = 25.82 × 64/8 = 206.5 kNm. 206.5 × 10⁶ / (0.90 × 300) = 765 × 10³ mm³ < 826 × 10³ mm³ — OK
Selected: 410UB69.0 Grade 300
Design Resources
- Australian Steel Grades
- Australian Steel Properties
- Australian Bolt Capacity
- AS 4100 Beam Design
- All Australian References
Frequently Asked Questions
What are the standard universal beam sizes in Australia? Australian UB sizes range from 150UB14.0 to 700UB173 per AS/NZS 3679.1. The designation gives nominal depth and mass per metre (e.g., 410UB59.7 is ~410 mm deep at 59.7 kg/m). The most commonly specified sizes are 250UB, 310UB, 360UB, 410UB, 530UB, and 610UB series.
What steel grade is standard for Australian universal beams? Grade 300 (fy = 300 MPa for flange thickness ≤ 11 mm, fy = 280 MPa for > 11 mm) per AS/NZS 3679.1. Grade 300PLUS provides guaranteed weldability and Charpy V-notch toughness. For higher strength requirements, Grade 400 is available but less common.
How do Australian UB sections compare to UK UB sections? Australian UBs follow similar nominal depths to UK UBs but differ in flange widths, web thicknesses, and mass per metre. A 410UB59.7 is approximately equivalent to UK 406×140UB46 but is heavier with thicker flanges. Always verify section properties directly, not by serial size alone.
What is the AS 4100 beam design capacity check? Per AS 4100 Clause 5.1: the design bending moment M* must not exceed the design section moment capacity phi Msx = phi × fy × Zex, where Zex is the effective section modulus accounting for flange and web slenderness. For compact sections (the most common case), Zex = Sx (plastic section modulus). Compactness is determined per AS 4100 Table 5.2.
What is the difference between a UB and a UC section? Universal beams (UB) have a depth-to-flange-width ratio typically > 1.5 and are optimized for bending resistance. Universal columns (UC) have flange widths close to the section depth and are optimized for axial compression. Australian UCs range from 150UC to 400UC series.
Educational reference only. Verify all values against the current edition of AS/NZS 3679.1 and AS 4100:2020. This information does not constitute professional engineering advice. Always consult a qualified structural engineer for design decisions.