SHS 250×250×8.8 vs SHS 260×260×8
SHS 250×250×8.8 is an SHS Hot-finished section from the UK Blue Book (SCI P363); SHS 260×260×8 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 758 cm³ against 753 cm³ of plastic modulus, a difference of 0.7%. SHS 260×260×8 is the lighter of the two at 62.8 kg/m against 66 kg/m, a saving of 5.1% on steel weight. SHS 260×260×8 is deeper, 260 mm against 250 mm, which matters where the floor zone is tight.
| Property | SHS 250×250×8.8 SHS Hot-finished | SHS 260×260×8 SHS | Difference |
|---|---|---|---|
| Mass | 66 kg/m | 62.8 kg/m | +5.1% |
| Depth | 250 mm | 260 mm | -3.8% |
| Width | 250 mm | 260 mm | -3.8% |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 84.1 cm² | 80 cm² | +5.1% |
| Second moment, major (Iy) | 8,110 cm⁴ | 8,423 cm⁴ | -3.7% |
| Plastic modulus, major (Wpl,y) | 758 cm³ | 753 cm³ | +0.7% |
| Elastic modulus, major (Wel,y) | 649 cm³ | 648 cm³ | +0.2% |
| Second moment, minor (Iz) | 8,110 cm⁴ | 8,423 cm⁴ | -3.7% |
| Plastic modulus, minor (Wpl,z) | 758 cm³ | 753 cm³ | +0.7% |
| Radius of gyration, minor (iz) | 9.82 cm | 10.3 cm | -4.7% |
| Torsion constant (It) | 12,600 cm⁴ | 13,010 cm⁴ | -3.2% |
SHS 250×250×8.8 to BS EN 10210-2:2006; SHS 260×260×8 to EN 10219 · Continental Steel. Difference is expressed relative to SHS 260×260×8.
How to choose between them
On stiffness, SHS 260×260×8 has the larger second moment of area: 8,423 cm⁴ against 8,110 cm⁴, a difference of 3.7%. 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, SHS 260×260×8 is the more efficient section: 12.0 against 11.5 cm³ per kg/m, 4.2% 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. SHS Hot-finished sections are specified to BS EN 10210-2:2006 and SHS 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 5.1% weight.
In short, SHS 250×250×8.8 is the stronger section and SHS 260×260×8 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.