Lightweight frames. Clean finish. Built for the long run.

Aluminium RHS is the smart choice when you want strength without the weight and better corrosion resistance than plain steel. It’s widely used across fabrication, fit-outs and light structural work, especially in coastal or wet environments where mild steel needs heavy coating or ongoing maintenance. Its great for architectural elements like window screens, hoods, and fencing and can be powder coated for a quality finish.

Steelmart stocks Aluminium RHS in a wide range of profiles and wall thicknesses, with square edge and radius edge options to suit both structural and architectural jobs. All profiles are supplied in 6.5m lengths, with cutting available on request (online orders include up to 3 straight cuts per item free, just add cut lengths in the checkout comments).

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What Is Aluminium RHS?

Aluminium RHS is a rectangular, hollow aluminium extrusion used for frames, supports and fabricated structures. The box shape gives excellent stiffness for its weight, and aluminium naturally forms a protective oxide layer that helps it resist corrosion in many environments.

At Steelmart, Aluminium RHS is available with:

  • Square edge (clean, sharp look)
  • Radius edge (smoother edge for safety and aesthetics) 

Sizes and thicknesses we stock

Steelmart’s Aluminium RHS range covers small, tidy sections right through to large structural sizes, including profiles from 12.7 × 12.7mm up to 300 × 50mm, with thicknesses from 1.2mm to 6.35mm.

Where Aluminium RHS performs best

These are the applications commonly used for Aluminium RHS:

  • Ute canopies, trays and lightweight vehicle builds (weight matters, easy handling)
  • Trailer frames and accessories (especially where rust is a constant battle)
  • Marine-adjacent and coastal fabrication (choose the right alloy and finishing for exposure)
  • Shopfitting and commercial fit-outs (clean lines, tidy finish, easy to clad)
  • Architectural frames and screening (square or radius edges depending on the look)
  • Racking, trolleys, guards and brackets in light industrial settings

Why choose Aluminium RHS over steel RHS?

  • Much lighter to handle: aluminium is around one-third the density of steel, which can make fabrication, lifting and transport easier.
  • Corrosion resistant: aluminium naturally resists corrosion in many outdoor and moisture-exposed environments.
    Clean finish options: square-edge for sharp architectural lines, radius-edge for smoother exposed edges.

(And a quick reality-check: aluminium doesn’t “never rust” — it doesn’t rust like steel, but it can still corrode in harsh conditions. Grade choice and finishing matter, especially near salt water.)

FAQ's

What is aluminium rhs?

Aluminium RHS stands for Rectangular Hollow Section — a rectangular, hollow aluminium extrusion used for frames and fabricated structures. It offers an excellent strength-to-weight balance and strong corrosion resistance in many environments, which makes it popular for lightweight frames, fit-outs, trailers, canopies, screening and outdoor fabrication.

(Accuracy note: aluminium doesn’t “rust” like steel, but it can still corrode in harsh conditions especially salty/coastal exposure — so alloy choice and finishing still matter.)

Can Aluminium RHS be welded?

Yes. Aluminium RHS is commonly TIG or MIG welded for frames, canopies, trailers, shopfitting and general fabrication. The best results come from:

  • using the right filler wire for the alloy
  • clean prep (remove contaminants/oxidation at the weld area)
  • correct settings and technique (aluminium moves heat fast)

If your job is structural or load-bearing, it’s worth confirming the welding procedure and design requirements.

Can Aluminium RHS be powder coated?

Yes — Aluminium RHS is often powder coated for a tougher finish and a clean architectural look. Powder coating also helps in exposed environments and is popular for:

  • screens and pergola-style frames
  • shopfitting and fit-outs
  • handrails and visible frames

Preparation matters (pre-treatment), especially for outdoor durability.

Do you cut Aluminium RHS to size, and what lengths do you supply?

Aluminium RHS is typically supplied in 6.5m lengths, and cut-to-size is available so you can reduce waste and speed up fabrication. If you’re ordering from a cut list, provide lengths in mm, quantities, and whether the cut ends will be visible (for finish expectations)

What’s the difference between square-edge and radius-edge Aluminium RHS?

  • Square-edge gives a sharper, more architectural look and is often chosen for exposed frames and modern fit-outs.

Radius-edge has softer corners, which can be better for handling, safety and certain finishing preferences.