Square Bars SQ
AS/NZS 3679.1Hot-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.
Click a column heading to sort. Grade 300 capacities.
| Designation | Mass kg/m | b mm | Ag mm² | Ix 10⁶mm⁴ | Zx 10³mm³ | Sx 10³mm³ | Iy 10⁶mm⁴ | ry mm | J 10³mm⁴ | φMsx kNm | φNs kN |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 75SQ | 44.2 | 75 | 5625 | 2.64 | 70.3 | 105 | 2.64 | 21.7 | 4449 | 27.5 | 1468 |
| 63SQ | 31.2 | 63 | 3969 | 1.31 | 41.7 | 62.5 | 1.31 | 18.2 | 2215 | 16.3 | 1036 |
| 50SQ | 19.6 | 50 | 2500 | 0.521 | 20.8 | 31.2 | 0.521 | 14.4 | 879 | 8.4 | 675 |
| 45SQ | 15.9 | 45 | 2025 | 0.342 | 15.2 | 22.8 | 0.342 | 13.0 | 577 | 6.2 | 547 |
| 40SQ | 12.6 | 40 | 1600 | 0.213 | 10.7 | 16.0 | 0.213 | 11.5 | 360 | 4.3 | 432 |
| 32SQ | 8.04 | 32 | 1024 | 0.0874 | 5.46 | 8.19 | 0.0874 | 9.2 | 147 | 2.2 | 276 |
| 25SQ | 4.91 | 25 | 625 | 0.0326 | 2.60 | 3.91 | 0.0326 | 7.2 | 54.9 | 1.1 | 169 |
| 20SQ | 3.14 | 20 | 400 | 0.0133 | 1.33 | 2.00 | 0.0133 | 5.8 | 22.5 | 0.5 | 108 |
| 16SQ | 2.01 | 16.0 | 256 | 0.00546 | 0.683 | 1.02 | 0.00546 | 4.6 | 9.21 | 0.3 | 69 |
| 12SQ | 1.13 | 12.0 | 144 | 0.00173 | 0.288 | 0.432 | 0.00173 | 3.5 | 2.92 | 0.1 | 39 |
| 10SQ | 0.78 | 10.0 | 100 | 0.000833 | 0.167 | 0.250 | 0.000833 | 2.9 | 1.41 | 0.1 | 27 |
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).