CHS 114.3×8 vs PIPE 4XS
CHS 114.3×8 is an CHS Hot-finished section from the UK Blue Book (SCI P363); PIPE 4XS is the closest equivalent in the American AISC Shapes Database. They are close to interchangeable in bending: 90.6 cm³ against 90.62 cm³ of plastic modulus, a difference of 0.0%. CHS 114.3×8 is the lighter of the two at 21 kg/m against 22.3 kg/m, a saving of 5.8% on steel weight. Both are about 114 mm deep, so either fits the same construction zone.
| Property | CHS 114.3×8 CHS Hot-finished | PIPE 4XS Pipe | Difference |
|---|---|---|---|
| Mass | 21 kg/m | 22.3 kg/m | -5.8% |
| Depth | 114.3 mm | 114.3 mm | same |
| Width | 114.3 mm | 114.3 mm | same |
| Web thickness | 0 mm | 8 mm | -100.0% |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 26.7 cm² | 26.7 cm² | same |
| Second moment, major (Iy) | 379 cm⁴ | 379.6 cm⁴ | -0.2% |
| Plastic modulus, major (Wpl,y) | 90.6 cm³ | 90.62 cm³ | same |
| Elastic modulus, major (Wel,y) | 66.4 cm³ | 66.368 cm³ | same |
| Second moment, minor (Iz) | 379 cm⁴ | 379.6 cm⁴ | -0.2% |
| Plastic modulus, minor (Wpl,z) | 90.6 cm³ | 90.62 cm³ | same |
| Radius of gyration, minor (iz) | 3.77 cm | 3.76 cm | +0.3% |
| Torsion constant (It) | 759 cm⁴ | 757.5 cm⁴ | +0.2% |
CHS 114.3×8 to BS EN 10210-2:2006; PIPE 4XS to AISC Shapes Database v16.0. Difference is expressed relative to PIPE 4XS.
How to choose between them
On stiffness, PIPE 4XS has the larger second moment of area: 379.6 cm⁴ against 379 cm⁴, a difference of 0.2%. 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, CHS 114.3×8 is the more efficient section: 4.3 against 4.1 cm³ per kg/m, 6.2% 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. 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 5.8% weight.
In short, PIPE 4XS is the stronger section and CHS 114.3×8 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.