Why “50×50 RHS” Is Actually SHS
One of the most common mix-ups in the steel industry is calling a 25x25mm, 50x50mm, or even a 75x75mm tube “RHS” when it’s technically SHS. The term RHS (Rectangular Hollow Section) is often used as a catch-all for any hollow steel tube, but this is technically incorrect. If all four sides are equal, like 50x50mm or 100x100mm, it’s a Square Hollow Section (SHS), not RHS. Understanding this distinction matters because SHS and RHS have different structural properties suited to different applications. At the same time, if you get it right, it makes our job as salespeople, even easier!
The Key Difference: Shape Defines Function
The fundamental difference comes down to geometry:
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SHS (Square Hollow Section): Equal width and height (e.g., 50x50mm, 100x100mm). Provides uniform strength in both directions, ideal for columns, posts, and multi-directional loads.
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RHS (Rectangular Hollow Section): Unequal width and height (e.g., 75x50mm, 100x50mm). Offers greater bending resistance along its longer axis, better suited for beams, lintels, and horizontal spans.
If you’re ordering “50×50 RHS,” you’re actually asking for SHS, and the distinction can affect your project’s structural performance and specifications.
When to Use SHS vs RHS
Choose SHS when loads come from multiple or unpredictable directions, such as freestanding posts or architectural features. Opt for RHS when spanning longer distances or where bending resistance in one direction is critical, like roof frames or pergolas.
Get It Right with Melsteel
At Melsteel, we stock both SHS and RHS in primed and galvanised finishes across a wide range of sizes. Our experienced team can help you select the correct section for your project, whether that’s genuine 50×50 SHS for your gate posts or 75×50 RHS for your structural beams. We offer custom cutting, fabrication, and Melbourne-wide delivery to ensure your order is right from specification to site.
Not sure which you need? Contact Melsteel at 03 8794 3100 or browse our hollow section range online. Our team will make sure you get exactly what your project requires, correctly named and precisely cut.
FAQs: SHS vs RHS Confusion
1. Is 50×50 steel RHS or SHS?
A 50x50mm tube is SHS (Square Hollow Section) because both sides are equal. RHS refers only to rectangular profiles with unequal dimensions.
2. Why do people call a square tube RHS?
RHS became a general term for hollow sections in some regions, but it’s technically incorrect for square profiles. Using the right terminology ensures accurate ordering.
3. Does the difference actually matter?
Yes, SHS and RHS have different load-bearing properties. Using the wrong section can affect structural integrity or lead to ordering errors.
4. Where can I get both SHS and RHS in Melbourne?
Melsteel stocks a comprehensive range of both SHS and RHS in various sizes and finishes, with expert advice to help you choose correctly.
Where to Next
– Square Hollow Sections: The Versatile Backbone of Modern Builds
– Why Rectangular Hollow Sections (RHS) Are Essential for Modern Construction
– Galvanised SHS – Square Hollow Section Steel: Uses, Benefits & Supply in Melbourne