Short answer: SHS is Square Hollow Section, RHS is Rectangular Hollow Section, CHS is Circular Hollow Section — which most people just call pipe. Same family of structural steel, three different shapes, each one better at a different job.
SHS — Square Hollow Section
Equal sides, square profile. Strong in every direction the same amount, which makes it the default pick for posts, columns and uprights. It also looks tidy face-on, so it gets used for gates, balustrades and exposed framing.
- Typical sizes: 20×20×1.6 up to 250×250×9.0
- Best for: posts, columns, vertical framing, gates, balustrading
- Lengths: 6.0m and 7.5m standard; cut-to-length on request
RHS — Rectangular Hollow Section
One side longer than the other. The extra depth in one direction gives RHS more bending strength on that axis, which makes it the right pick for beams, lintels and horizontal members that need to span a distance without sagging.
- Typical sizes: 50×25 up to 250×150
- Best for: beams, lintels, patio rafters, anywhere you need stiffness in one direction
- Orient it with the long face vertical when carrying load down
CHS — Circular Hollow Section (pipe)
Round profile, equal strength in every direction like SHS but with no corners to catch on. CHS is the right pick for handrails, bollards, exposed posts where people will brush past, and any job where the round shape is part of the design.
- Typical sizes: 15NB up to 150NB
- Best for: handrails, balustrade posts, bollards, fence posts, plumbing and fittings
- Available in galvanised and black
When to choose what
| The job | Best pick | Why |
|---|---|---|
| Patio or shed post | SHS | Equal strength all ways, clean look |
| Patio rafter / beam | RHS | Extra depth = more spanning strength |
| Handrail or balustrade | CHS or SHS | CHS for soft feel, SHS for modern look |
| Gate frame | SHS | Square corners weld cleanly to hinges |
| Pool fence posts | SHS or CHS | Either, both galvanise well |
| Bollard | CHS | No corners, harder to damage |
Finishes available
All three come in painted, DuraGal and hot-dip galvanised. On the Gold Coast we stock the common sizes and finishes ready to walk out the door — anything less common we'll source. Drop into the yard, send a list, or use our quote form and we'll get you a price.
See all three on the products page.
