RHS 260×140×8 vs RHS 250×150×8
RHS 260×140×8 is an RHS Hot-finished section from the UK Blue Book (SCI P363); RHS 250×150×8 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 511 cm³ against 501 cm³ of plastic modulus, a difference of 2.0%. They weigh essentially the same, 47.7 kg/m and 48 kg/m. RHS 260×140×8 is deeper, 260 mm against 250 mm, which matters where the floor zone is tight.
| Property | RHS 260×140×8 RHS Hot-finished | RHS 250×150×8 RHS | Difference |
|---|---|---|---|
| Mass | 47.7 kg/m | 48 kg/m | -0.6% |
| Depth | 260 mm | 250 mm | +4.0% |
| Width | 140 mm | 150 mm | -6.7% |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 60.8 cm² | 60.8 cm² | same |
| Second moment, major (Iy) | 5,370 cm⁴ | 5,111 cm⁴ | +5.1% |
| Plastic modulus, major (Wpl,y) | 511 cm³ | 501 cm³ | +2.0% |
| Elastic modulus, major (Wel,y) | 413 cm³ | 409 cm³ | +1.0% |
| Second moment, minor (Iz) | 2,030 cm⁴ | 2,298 cm⁴ | -11.7% |
| Plastic modulus, minor (Wpl,z) | 331 cm³ | 350 cm³ | -5.4% |
| Radius of gyration, minor (iz) | 5.78 cm | 6.15 cm | -6.0% |
| Torsion constant (It) | 4,700 cm⁴ | 5,021 cm⁴ | -6.4% |
RHS 260×140×8 to BS EN 10210-2:2006; RHS 250×150×8 to EN 10219 · Continental Steel. Difference is expressed relative to RHS 250×150×8.
How to choose between them
On stiffness, RHS 260×140×8 has the larger second moment of area: 5,370 cm⁴ against 5,111 cm⁴, a difference of 5.1%. This matters more often than the strength comparison, because on normal floor spans deflection rather than bending capacity sets the beam size - so if the two are close on modulus but apart on inertia, the stiffer one is usually the better answer even when it is not the stronger one.
Measured as bending capacity per kilogram of steel, RHS 260×140×8 is the more efficient section: 10.7 against 10.4 cm³ per kg/m, 2.6% better. Over a floor of repeated beams that difference is real tonnage, though it is often outweighed by whichever section the fabricator can actually source.
These come from different catalogues, so treat the swap as a design change rather than a like-for-like substitution. RHS Hot-finished sections are specified to BS EN 10210-2:2006 and RHS to EN 10219 · Continental Steel; the steel grades, tolerances and available lengths differ, connection details and bolt gauges are set out differently, and the two are rarely both stocked in the same market. Check availability before changing a section on a drawing to save a marginal amount of weight.
In short, these two are genuine equivalents. Pick whichever your supplier stocks and the rest of the frame already uses.