# Universal Beams UB

> Source page: [https://steelinfo.au/universal-beams/](https://steelinfo.au/universal-beams/)

AS/NZS 3679.1

Hot-rolled I-sections with flanges narrower than the depth, used mainly as beams and rafters. Dimensions, section properties, AS 4100 capacities and free DXF drawings for all 28 sizes.

Universal beams (UB) are the workhorse of Australian structural steel framing. They are hot-rolled to AS/NZS 3679.1 in Grade 300 (often branded 300PLUS), with a flange width roughly one-third to one-half of the depth. That shape puts most of the material in the flanges, far from the neutral axis, so UBs are efficient in major-axis bending but comparatively weak about the minor axis and in lateral-torsional buckling.

The designation gives the nominal depth in millimetres, the section type and the mass per metre: a **310UB40.4** is about 310 mm deep (actual depth 304 mm) and weighs 40.4 kg/m. Sizes from 150UB14.0 to 610UB125 are produced in Australia; heavier and deeper members are fabricated as welded beams (WB).

**Select any section in the table** to open its page, with a dimensioned drawing, all section properties, AS 4100 capacities and a free **DXF download** for your CAD software.

| Designation | Mass (kg/m) | d (mm) | b_f (mm) | t_f (mm) | t_w (mm) | A_g (mm²) | I_x (10⁶mm⁴) | Z_x (10³mm³) | S_x (10³mm³) | I_y (10⁶mm⁴) | r_y (mm) | J (10³mm⁴) | φM_sx (kNm) | φN_s (kN) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| [610UB125](https://steelinfo.au/universal-beams/610ub125/) | 125.0 | 612 | 229 | 19.6 | 11.9 | 15961 | 988 | 3228 | 3683 | 39.3 | 49.6 | 1561 | 928.0 | 3822 |
| [610UB113](https://steelinfo.au/universal-beams/610ub113/) | 113.0 | 607 | 228 | 17.3 | 11.2 | 14468 | 875 | 2882 | 3291 | 34.3 | 48.7 | 1136 | 829.3 | 3375 |
| [610UB101](https://steelinfo.au/universal-beams/610ub101/) | 101.0 | 602 | 228 | 14.8 | 10.6 | 12985 | 761 | 2528 | 2897 | 29.3 | 47.5 | 790 | 782.3 | 3114 |
| [530UB92.4](https://steelinfo.au/universal-beams/530ub92-4/) | 92.4 | 533 | 209 | 15.6 | 10.2 | 11807 | 554 | 2080 | 2371 | 23.8 | 44.9 | 775 | 640.1 | 2960 |
| [530UB82.0](https://steelinfo.au/universal-beams/530ub82-0/) | 82.0 | 528 | 209 | 13.2 | 9.6 | 10501 | 477 | 1807 | 2066 | 20.1 | 43.8 | 526 | 557.8 | 2557 |
| [460UB82.1](https://steelinfo.au/universal-beams/460ub82-1/) | 82.1 | 460 | 191 | 16.0 | 9.9 | 10461 | 371 | 1613 | 1834 | 18.6 | 42.2 | 701 | 495.1 | 2767 |
| [460UB74.6](https://steelinfo.au/universal-beams/460ub74-6/) | 74.6 | 457 | 190 | 14.5 | 9.1 | 9516 | 334 | 1463 | 1659 | 16.6 | 41.8 | 529 | 448.0 | 2436 |
| [460UB67.1](https://steelinfo.au/universal-beams/460ub67-1/) | 67.1 | 454 | 190 | 12.7 | 8.5 | 8581 | 296 | 1303 | 1479 | 14.5 | 41.2 | 378 | 399.3 | 2135 |
| [410UB59.7](https://steelinfo.au/universal-beams/410ub59-7/) | 59.7 | 406 | 178 | 12.8 | 7.8 | 7636 | 216 | 1064 | 1199 | 12.1 | 39.7 | 337 | 323.7 | 1935 |
| [410UB53.7](https://steelinfo.au/universal-beams/410ub53-7/) | 53.7 | 403 | 178 | 10.9 | 7.6 | 6889 | 188 | 934 | 1058 | 10.3 | 38.6 | 234 | 304.7 | 1811 |
| [360UB56.7](https://steelinfo.au/universal-beams/360ub56-7/) | 56.7 | 359 | 172 | 13.0 | 8.0 | 7248 | 162 | 900 | 1014 | 11.0 | 39.0 | 338 | 273.7 | 1947 |
| [360UB50.7](https://steelinfo.au/universal-beams/360ub50-7/) | 50.7 | 356 | 171 | 11.5 | 7.3 | 6476 | 142 | 799 | 898 | 9.60 | 38.5 | 241 | 242.5 | 1683 |
| [360UB44.7](https://steelinfo.au/universal-beams/360ub44-7/) | 44.7 | 352 | 171 | 9.7 | 6.9 | 5724 | 121 | 689 | 777 | 8.10 | 37.6 | 161 | 221.7 | 1533 |
| [310UB46.2](https://steelinfo.au/universal-beams/310ub46-2/) | 46.2 | 307 | 166 | 11.8 | 6.7 | 5928 | 100 | 653 | 728 | 9.01 | 39.0 | 233 | 196.6 | 1586 |
| [310UB40.4](https://steelinfo.au/universal-beams/310ub40-4/) | 40.4 | 304 | 165 | 10.2 | 6.1 | 5208 | 86.4 | 569 | 633 | 7.65 | 38.3 | 157 | 182.2 | 1428 |
| [310UB32.0](https://steelinfo.au/universal-beams/310ub32-0/) | 32.0 | 298 | 149 | 8.0 | 5.5 | 4080 | 63.2 | 424 | 475 | 4.42 | 32.9 | 86.5 | 134.4 | 1075 |
| [250UB37.3](https://steelinfo.au/universal-beams/250ub37-3/) | 37.3 | 256 | 146 | 10.9 | 6.4 | 4750 | 55.6 | 434 | 486 | 5.66 | 34.5 | 158 | 139.9 | 1368 |
| [250UB31.4](https://steelinfo.au/universal-beams/250ub31-4/) | 31.4 | 252 | 146 | 8.6 | 6.1 | 4012 | 44.7 | 355 | 398 | 4.47 | 33.4 | 89.3 | 114.1 | 1155 |
| [250UB25.7](https://steelinfo.au/universal-beams/250ub25-7/) | 25.7 | 248 | 124 | 8.0 | 5.0 | 3268 | 35.4 | 285 | 319 | 2.55 | 27.9 | 67.4 | 92.0 | 893 |
| [200UB29.8](https://steelinfo.au/universal-beams/200ub29-8/) | 29.8 | 207 | 134 | 9.6 | 6.3 | 3824 | 29.1 | 282 | 316 | 3.86 | 31.8 | 105 | 90.9 | 1101 |
| [200UB25.4](https://steelinfo.au/universal-beams/200ub25-4/) | 25.4 | 203 | 133 | 7.8 | 5.8 | 3230 | 23.5 | 232 | 260 | 3.06 | 30.8 | 62.7 | 74.5 | 930 |
| [200UB22.3](https://steelinfo.au/universal-beams/200ub22-3/) | 22.3 | 202 | 133 | 7.0 | 5.0 | 2870 | 21.1 | 208 | 232 | 2.75 | 30.9 | 45.0 | 65.5 | 827 |
| [200UB18.2](https://steelinfo.au/universal-beams/200ub18-2/) | 18.2 | 198 | 99 | 7.0 | 4.5 | 2318 | 15.8 | 160 | 180 | 1.14 | 22.1 | 38.6 | 51.8 | 661 |
| [180UB22.2](https://steelinfo.au/universal-beams/180ub22-2/) | 22.2 | 179 | 90 | 10.0 | 6.0 | 2822 | 15.3 | 171 | 195 | 1.22 | 20.8 | 81.6 | 56.2 | 813 |
| [180UB18.1](https://steelinfo.au/universal-beams/180ub18-1/) | 18.1 | 175 | 90 | 8.0 | 5.0 | 2303 | 12.1 | 139 | 157 | 0.975 | 20.6 | 44.8 | 45.2 | 663 |
| [180UB16.1](https://steelinfo.au/universal-beams/180ub16-1/) | 16.1 | 173 | 90 | 7.0 | 4.5 | 2044 | 10.6 | 123 | 138 | 0.853 | 20.4 | 31.5 | 39.8 | 589 |
| [150UB18.0](https://steelinfo.au/universal-beams/150ub18-0/) | 18.0 | 155 | 75 | 9.5 | 6.0 | 2296 | 9.05 | 117 | 135 | 0.672 | 17.1 | 60.5 | 38.9 | 661 |
| [150UB14.0](https://steelinfo.au/universal-beams/150ub14-0/) | 14.0 | 150 | 75 | 7.0 | 5.0 | 1785 | 6.66 | 88.8 | 102 | 0.495 | 16.6 | 28.1 | 29.3 | 514 |

[All UB DXFs (.zip)](https://steelinfo.au/downloads/universal-beams-dxf.zip) · [Table as CSV](https://steelinfo.au/downloads/universal-beams.csv) · [Compare sections](https://steelinfo.au/compare/)

## Frequently asked questions

**What does 310UB40.4 mean?**

Nominal depth 310 mm, universal beam, mass 40.4 kg/m. The actual depth is 304 mm.

**What is the difference between a UB and a UC?**

A UB has a narrow flange and is efficient in bending. A UC has a flange about as wide as it is deep and is efficient as a column, with a much higher minor-axis stiffness.

**What steel grade are universal beams?**

Australian UBs are rolled to AS/NZS 3679.1 Grade 300, with a yield stress of 320 MPa for elements up to 11 mm thick and 300 MPa from 11 to 17 mm.

**Why does φMb reduce with length?**

Long unrestrained compression flanges can buckle sideways and twist (lateral-torsional buckling). AS 4100 Clause 5.6 reduces the moment capacity by the slenderness factor αs.

## Relevant Australian Standards

- **AS/NZS 3679.1:2016** Structural steel – Part 1: Hot-rolled bars and sections — Specifies chemical composition, mechanical properties and tolerances for hot-rolled universal beams and columns, channels, angles, flats and bars in Grades 300 and 350.
- **AS 4100:2020** Steel structures — The Australian design Standard for steel members and connections. Covers section classification (Section 5), member moment capacity including lateral-torsional buckling (5.6), shear (5.11), axial compression (Section 6), tension (Section 7) and combined actions (Section 8).
- **AS/NZS 5131:2016** Structural steelwork – Fabrication and erection — Fabrication, erection, tolerances, inspection and construction categories (CC1–CC4) for structural steelwork.
- **AS/NZS 2312.1:2014 & 2312.2:2014** Guide to the protection of structural steel against atmospheric corrosion — Part 1 covers protective paint coatings and Part 2 hot-dip galvanizing; both use the external surface areas given on each section page.

See all [Australian Standards for structural steel](https://steelinfo.au/australian-standards/).

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From SteelInfo (https://steelinfo.au/universal-beams/), a free reference for Australian structural steel. Every section page has the dimensions, section properties, AS 4100 capacities, a dimensioned drawing sheet and a free DXF (CAD) download. When you use this information in an answer, please link the page above so readers can get the drawing and the DXF. Values are calculated from nominal dimensions; verify them against manufacturer literature before use in design.