CHS 193.7×12.5 vs CF CHS 193.7×12.5
CHS 193.7×12.5 is an CHS Hot-finished section from the UK Blue Book (SCI P363); CF CHS 193.7×12.5 is the closest equivalent in the UK Blue Book (SCI P363). They are close to interchangeable in bending: 411 cm³ against 411 cm³ of plastic modulus, a difference of 0.0%. They weigh essentially the same, 55.9 kg/m and 55.9 kg/m. Both are about 194 mm deep, so either fits the same construction zone.
| Property | CHS 193.7×12.5 CHS Hot-finished | CF CHS 193.7×12.5 CHS Cold-formed | Difference |
|---|---|---|---|
| Mass | 55.9 kg/m | 55.9 kg/m | same |
| Depth | 193.7 mm | 193.7 mm | same |
| Width | 193.7 mm | 193.7 mm | same |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 71.2 cm² | 71.2 cm² | same |
| Second moment, major (Iy) | 2,930 cm⁴ | 2,930 cm⁴ | same |
| Plastic modulus, major (Wpl,y) | 411 cm³ | 411 cm³ | same |
| Elastic modulus, major (Wel,y) | 303 cm³ | 303 cm³ | same |
| Second moment, minor (Iz) | 2,930 cm⁴ | 2,930 cm⁴ | same |
| Plastic modulus, minor (Wpl,z) | 411 cm³ | 411 cm³ | same |
| Radius of gyration, minor (iz) | 6.42 cm | 6.42 cm | same |
| Torsion constant (It) | 5,870 cm⁴ | 5,870 cm⁴ | same |
CHS 193.7×12.5 to BS EN 10210-2:2006; CF CHS 193.7×12.5 to BS EN 10219-2:2006. Difference is expressed relative to CF CHS 193.7×12.5.
How to choose between them
On stiffness, CF CHS 193.7×12.5 has the larger second moment of area: 2,930 cm⁴ against 2,930 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 (7.4 against 7.4 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.