RHS 260×140×12.5 vs RHS 250×150×12.5
RHS 260×140×12.5 is an RHS Hot-finished section from the UK Blue Book (SCI P363); RHS 250×150×12.5 is the closest equivalent in the European (Continental) range. RHS 260×140×12.5 carries more bending: 756 cm³ of plastic modulus against 740 cm³, 2.2% more. They weigh essentially the same, 72.3 kg/m and 73 kg/m. RHS 260×140×12.5 is deeper, 260 mm against 250 mm, which matters where the floor zone is tight.
| Property | RHS 260×140×12.5 RHS Hot-finished | RHS 250×150×12.5 RHS | Difference |
|---|---|---|---|
| Mass | 72.3 kg/m | 73 kg/m | -1.0% |
| 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 | 92.1 cm² | 92.1 cm² | same |
| Second moment, major (Iy) | 7,770 cm⁴ | 7,387 cm⁴ | +5.2% |
| Plastic modulus, major (Wpl,y) | 756 cm³ | 740 cm³ | +2.2% |
| Elastic modulus, major (Wel,y) | 597 cm³ | 591 cm³ | +1.0% |
| Second moment, minor (Iz) | 2,880 cm⁴ | 3,265 cm⁴ | -11.8% |
| Plastic modulus, minor (Wpl,z) | 485 cm³ | 514 cm³ | -5.6% |
| Radius of gyration, minor (iz) | 5.59 cm | 5.96 cm | -6.2% |
| Torsion constant (It) | 6,840 cm⁴ | 7,326 cm⁴ | -6.6% |
RHS 260×140×12.5 to BS EN 10210-2:2006; RHS 250×150×12.5 to EN 10219 · Continental Steel. Difference is expressed relative to RHS 250×150×12.5.
How to choose between them
On stiffness, RHS 260×140×12.5 has the larger second moment of area: 7,770 cm⁴ against 7,387 cm⁴, a difference of 5.2%. 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 260×140×12.5 is the more efficient section: 10.5 against 10.1 cm³ per kg/m, 3.2% 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, RHS 260×140×12.5 is the stronger section and RHS 260×140×12.5 is the lighter one; where those are the same section, it is the clear choice, and where they are not, decide on whether your design is governed by capacity or by tonnage.