RHSSteel
Rectangular hollow sections (RHS) — cold-formed structural tube for framing, posts and fabrication.
Rectangular hollow section (RHS) is cold-formed structural steel tube with a rectangular profile, widely used for steel frames, posts, trailers, gates and general fabrication. Because RHS has flat faces on all four sides, it is the go-to section for welded RHS steel frames — portal frames, shed and carport frames, mezzanines, machinery bases and trailer chassis — where members need to be cut, mitred and welded quickly with simple connections. We supply RHS in the full range of sizes from 50×25 to 400×300, in wall thicknesses to suit, manufactured to AS/NZS 1163 in Grade C350L0 and C450L0. Available black (oiled), painted or galvanised with mill test certificates and full traceability.
Product Range
Full Size Range
RHS from 50×25mm up to 400×300mm in wall thicknesses from 1.6mm to 16mm to suit structural and fabrication needs.
Structural Grades
Manufactured to AS/NZS 1163 in Grade C350L0 and C450L0 for verified strength and weldability.
Black, Painted & Galvanised
Supplied black (oiled), in-line painted, or pre-galvanised for corrosion protection.
Cut-to-Length
Cutting to your specified lengths to reduce wastage and on-site handling.
RHS Steel Frames
RHS for welded steel frames — portal frames, shed and carport frames, mezzanine and platform frames, equipment skids and trailer chassis. Supplied as straight lengths, cut-to-length kits or as fully fabricated frames to your drawings.
Size Charts & Sections
Dimensions, mass per metre and section properties available to support structural design.
RHS (Rectangular Hollow Section) Sizes
Common Australian RHS sizes to AS/NZS 1163 in Grade C350L0 / C450L0. Available black, painted or pre-galvanised.
| Size D × B (mm) | Wall thickness (mm) |
|---|---|
| 50 × 25 | 1.6 – 3.0 |
| 65 × 35 | 2.0 – 3.0 |
| 75 × 50 | 2.0 – 4.0 |
| 100 × 50 | 2.0 – 6.0 |
| 125 × 75 | 3.0 – 6.0 |
| 150 × 50 | 3.0 – 6.0 |
| 150 × 100 | 4.0 – 9.0 |
| 200 × 100 | 4.0 – 9.0 |
| 250 × 150 | 5.0 – 12.0 |
| 300 × 200 | 6.0 – 12.5 |
| 400 × 300 | 8.0 – 16.0 |
Additional sizes, grades, lengths and finishes available on request — contact us for a full size chart and quote.
Common Applications
- RHS steel frames — portal, shed, carport and mezzanine frames
- Posts, columns and bollards
- Trailers, gates and machinery frames
- Mezzanines, platforms and balustrades
- General fabrication and engineering
Relevant Standards
- AS/NZS 1163 — Cold-formed structural steel hollow sections
- AS 4100 — Steel structures
- AS/NZS 1554 — Structural steel welding
RHS Steel — Frequently Asked Questions
What RHS sizes do you supply?
From 50 × 25 up to 400 × 300 mm in wall thicknesses from 1.6 to 16 mm, to AS/NZS 1163 in Grade C350L0 and C450L0, in 8 metre standard lengths or cut to length.
Is RHS suitable for steel frames?
Yes. RHS has flat faces on all four sides, which makes it the standard choice for welded steel frames such as portal frames, shed and carport frames, mezzanines, trailer chassis and equipment skids. We supply straight lengths, cut kits or fully fabricated frames.
What is the difference between C350 and C450 RHS?
The grade is the minimum yield strength in MPa. C450L0 is stronger, so a lighter section can carry the same load, while C350L0 is the general-purpose grade. Both carry the L0 impact-tested designation for use down to 0 °C.
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