CHS 273×12.5 vs PIPE 10XS
CHS 273×12.5 is an CHS Hot-finished section from the UK Blue Book (SCI P363); PIPE 10XS is the closest equivalent in the American AISC Shapes Database. CHS 273×12.5 carries more bending: 849 cm³ of plastic modulus against 806.24 cm³, 5.3% more. They weigh essentially the same, 80.3 kg/m and 81.6 kg/m. Both are about 273 mm deep, so either fits the same construction zone.
| Property | CHS 273×12.5 CHS Hot-finished | PIPE 10XS Pipe | Difference |
|---|---|---|---|
| Mass | 80.3 kg/m | 81.6 kg/m | -1.6% |
| Depth | 273 mm | 273.1 mm | same |
| Width | 273 mm | 273.1 mm | same |
| Web thickness | 0 mm | 11.8 mm | -100.0% |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 102 cm² | 97.4 cm² | +4.7% |
| Second moment, major (Iy) | 8,700 cm⁴ | 8,283 cm⁴ | +5.0% |
| Plastic modulus, major (Wpl,y) | 849 cm³ | 806.24 cm³ | +5.3% |
| Elastic modulus, major (Wel,y) | 637 cm³ | 606.32 cm³ | +5.1% |
| Second moment, minor (Iz) | 8,700 cm⁴ | 8,283 cm⁴ | +5.0% |
| Plastic modulus, minor (Wpl,z) | 849 cm³ | 806.24 cm³ | +5.3% |
| Radius of gyration, minor (iz) | 9.22 cm | 9.25 cm | -0.3% |
| Torsion constant (It) | 17,400 cm⁴ | 16,566 cm⁴ | +5.0% |
CHS 273×12.5 to BS EN 10210-2:2006; PIPE 10XS to AISC Shapes Database v16.0. Difference is expressed relative to PIPE 10XS.
How to choose between them
On stiffness, CHS 273×12.5 has the larger second moment of area: 8,700 cm⁴ against 8,283 cm⁴, a difference of 5.0%. 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, CHS 273×12.5 is the more efficient section: 10.6 against 9.9 cm³ per kg/m, 7.0% 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. CHS Hot-finished sections are specified to BS EN 10210-2:2006 and Pipe to AISC Shapes Database v16.0; 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, CHS 273×12.5 is the stronger section and CHS 273×12.5 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.