CHS 219.1×8 vs CF CHS 219.1×8
CHS 219.1×8 is an CHS Hot-finished section from the UK Blue Book (SCI P363); CF CHS 219.1×8 is the closest equivalent in the UK Blue Book (SCI P363). They are close to interchangeable in bending: 357 cm³ against 357 cm³ of plastic modulus, a difference of 0.0%. They weigh essentially the same, 41.6 kg/m and 41.6 kg/m. Both are about 219 mm deep, so either fits the same construction zone.
| Property | CHS 219.1×8 CHS Hot-finished | CF CHS 219.1×8 CHS Cold-formed | Difference |
|---|---|---|---|
| Mass | 41.6 kg/m | 41.6 kg/m | same |
| Depth | 219.1 mm | 219.1 mm | same |
| Width | 219.1 mm | 219.1 mm | same |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 53.1 cm² | 53.1 cm² | same |
| Second moment, major (Iy) | 2,960 cm⁴ | 2,960 cm⁴ | same |
| Plastic modulus, major (Wpl,y) | 357 cm³ | 357 cm³ | same |
| Elastic modulus, major (Wel,y) | 270 cm³ | 270 cm³ | same |
| Second moment, minor (Iz) | 2,960 cm⁴ | 2,960 cm⁴ | same |
| Plastic modulus, minor (Wpl,z) | 357 cm³ | 357 cm³ | same |
| Radius of gyration, minor (iz) | 7.47 cm | 7.47 cm | same |
| Torsion constant (It) | 5,920 cm⁴ | 5,920 cm⁴ | same |
CHS 219.1×8 to BS EN 10210-2:2006; CF CHS 219.1×8 to BS EN 10219-2:2006. Difference is expressed relative to CF CHS 219.1×8.
How to choose between them
On stiffness, CF CHS 219.1×8 has the larger second moment of area: 2,960 cm⁴ against 2,960 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 (8.6 against 8.6 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.