# Square Bars SQ

> Source page: [https://steelinfo.au/square-bar/](https://steelinfo.au/square-bar/)

AS/NZS 3679.1

Hot-rolled square bar, used for balustrade pickets, gates, keys and general fabrication. Dimensions, section properties, AS 4100 capacities and free DXF drawings for all 11 sizes.

Hot-rolled square bar to AS/NZS 3679.1, used for balustrade pickets, gates, keys and general fabrication.

Mass per metre = 0.00785 × b² kg/m (b in mm), so a 25SQ weighs 4.91 kg/m. The torsion constant of a square is J = 0.1406b⁴.

**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) | b (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) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| [75SQ](https://steelinfo.au/square-bar/75sq/) | 44.2 | 75 | 5625 | 2.64 | 70.3 | 105 | 2.64 | 21.7 | 4449 | 27.5 | 1468 |
| [63SQ](https://steelinfo.au/square-bar/63sq/) | 31.2 | 63 | 3969 | 1.31 | 41.7 | 62.5 | 1.31 | 18.2 | 2215 | 16.3 | 1036 |
| [50SQ](https://steelinfo.au/square-bar/50sq/) | 19.6 | 50 | 2500 | 0.521 | 20.8 | 31.2 | 0.521 | 14.4 | 879 | 8.4 | 675 |
| [45SQ](https://steelinfo.au/square-bar/45sq/) | 15.9 | 45 | 2025 | 0.342 | 15.2 | 22.8 | 0.342 | 13.0 | 577 | 6.2 | 547 |
| [40SQ](https://steelinfo.au/square-bar/40sq/) | 12.6 | 40 | 1600 | 0.213 | 10.7 | 16.0 | 0.213 | 11.5 | 360 | 4.3 | 432 |
| [32SQ](https://steelinfo.au/square-bar/32sq/) | 8.04 | 32 | 1024 | 0.0874 | 5.46 | 8.19 | 0.0874 | 9.2 | 147 | 2.2 | 276 |
| [25SQ](https://steelinfo.au/square-bar/25sq/) | 4.91 | 25 | 625 | 0.0326 | 2.60 | 3.91 | 0.0326 | 7.2 | 54.9 | 1.1 | 169 |
| [20SQ](https://steelinfo.au/square-bar/20sq/) | 3.14 | 20 | 400 | 0.0133 | 1.33 | 2.00 | 0.0133 | 5.8 | 22.5 | 0.5 | 108 |
| [16SQ](https://steelinfo.au/square-bar/16sq/) | 2.01 | 16.0 | 256 | 0.00546 | 0.683 | 1.02 | 0.00546 | 4.6 | 9.21 | 0.3 | 69 |
| [12SQ](https://steelinfo.au/square-bar/12sq/) | 1.13 | 12.0 | 144 | 0.00173 | 0.288 | 0.432 | 0.00173 | 3.5 | 2.92 | 0.1 | 39 |
| [10SQ](https://steelinfo.au/square-bar/10sq/) | 0.78 | 10.0 | 100 | 0.000833 | 0.167 | 0.250 | 0.000833 | 2.9 | 1.41 | 0.1 | 27 |

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

## Frequently asked questions

**How much does square bar weigh?**

Mass per metre = 0.00785 × b² (b in mm). A 25SQ is 4.91 kg/m; a 50SQ is 19.6 kg/m.

## 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).

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

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From SteelInfo (https://steelinfo.au/square-bar/), 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.