CHS 168.3×10 vs CF CHS 168.3×10
CHS 168.3×10 is an CHS Hot-finished section from the UK Blue Book (SCI P363); CF CHS 168.3×10 is the closest equivalent in the UK Blue Book (SCI P363). They are close to interchangeable in bending: 251 cm³ against 251 cm³ of plastic modulus, a difference of 0.0%. They weigh essentially the same, 39 kg/m and 39 kg/m. Both are about 168 mm deep, so either fits the same construction zone.
| Property | CHS 168.3×10 CHS Hot-finished | CF CHS 168.3×10 CHS Cold-formed | Difference |
|---|---|---|---|
| Mass | 39 kg/m | 39 kg/m | same |
| Depth | 168.3 mm | 168.3 mm | same |
| Width | 168.3 mm | 168.3 mm | same |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 49.7 cm² | 49.7 cm² | same |
| Second moment, major (Iy) | 1,560 cm⁴ | 1,560 cm⁴ | same |
| Plastic modulus, major (Wpl,y) | 251 cm³ | 251 cm³ | same |
| Elastic modulus, major (Wel,y) | 186 cm³ | 186 cm³ | same |
| Second moment, minor (Iz) | 1,560 cm⁴ | 1,560 cm⁴ | same |
| Plastic modulus, minor (Wpl,z) | 251 cm³ | 251 cm³ | same |
| Radius of gyration, minor (iz) | 5.61 cm | 5.61 cm | same |
| Torsion constant (It) | 3,130 cm⁴ | 3,130 cm⁴ | same |
CHS 168.3×10 to BS EN 10210-2:2006; CF CHS 168.3×10 to BS EN 10219-2:2006. Difference is expressed relative to CF CHS 168.3×10.
How to choose between them
On stiffness, CF CHS 168.3×10 has the larger second moment of area: 1,560 cm⁴ against 1,560 cm⁴, a difference of 0.0%. 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, the two are equally efficient (6.4 against 6.4 cm³ per kg/m), so on a pure steel-tonnage basis there is nothing to choose between them. The decision comes down to availability, connection detailing and what the rest of the frame uses.
In short, these two are genuine equivalents. Pick whichever your supplier stocks and the rest of the frame already uses.