CHS 244.5×6.3 vs CF CHS 244.5×6.3
CHS 244.5×6.3 is an CHS Hot-finished section from the UK Blue Book (SCI P363); CF CHS 244.5×6.3 is the closest equivalent in the UK Blue Book (SCI P363). They are close to interchangeable in bending: 358 cm³ against 358 cm³ of plastic modulus, a difference of 0.0%. They weigh essentially the same, 37 kg/m and 37 kg/m. Both are about 245 mm deep, so either fits the same construction zone.
| Property | CHS 244.5×6.3 CHS Hot-finished | CF CHS 244.5×6.3 CHS Cold-formed | Difference |
|---|---|---|---|
| Mass | 37 kg/m | 37 kg/m | same |
| Depth | 244.5 mm | 244.5 mm | same |
| Width | 244.5 mm | 244.5 mm | same |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 47.1 cm² | 47.1 cm² | same |
| Second moment, major (Iy) | 3,350 cm⁴ | 3,350 cm⁴ | same |
| Plastic modulus, major (Wpl,y) | 358 cm³ | 358 cm³ | same |
| Elastic modulus, major (Wel,y) | 274 cm³ | 274 cm³ | same |
| Second moment, minor (Iz) | 3,350 cm⁴ | 3,350 cm⁴ | same |
| Plastic modulus, minor (Wpl,z) | 358 cm³ | 358 cm³ | same |
| Radius of gyration, minor (iz) | 8.42 cm | 8.42 cm | same |
| Torsion constant (It) | 6,690 cm⁴ | 6,690 cm⁴ | same |
CHS 244.5×6.3 to BS EN 10210-2:2006; CF CHS 244.5×6.3 to BS EN 10219-2:2006. Difference is expressed relative to CF CHS 244.5×6.3.
How to choose between them
On stiffness, CF CHS 244.5×6.3 has the larger second moment of area: 3,350 cm⁴ against 3,350 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 (9.7 against 9.7 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.