RHS 200×150×10 vs CF RHS 200×150×10
RHS 200×150×10 is an RHS Hot-finished section from the UK Blue Book (SCI P363); CF RHS 200×150×10 is the closest equivalent in the UK Blue Book (SCI P363). RHS 200×150×10 carries more bending: 436 cm³ of plastic modulus against 413 cm³, 5.6% more. CF RHS 200×150×10 is the lighter of the two at 49.1 kg/m against 51 kg/m, a saving of 3.9% on steel weight. Both are about 200 mm deep, so either fits the same construction zone.
| Property | RHS 200×150×10 RHS Hot-finished | CF RHS 200×150×10 RHS Cold-formed | Difference |
|---|---|---|---|
| Mass | 51 kg/m | 49.1 kg/m | +3.9% |
| Depth | 200 mm | 200 mm | same |
| Width | 150 mm | 150 mm | same |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 64.9 cm² | 62.6 cm² | +3.7% |
| Second moment, major (Iy) | 3,570 cm⁴ | 3,350 cm⁴ | +6.6% |
| Plastic modulus, major (Wpl,y) | 436 cm³ | 413 cm³ | +5.6% |
| Elastic modulus, major (Wel,y) | 357 cm³ | 335 cm³ | +6.6% |
| Second moment, minor (Iz) | 2,260 cm⁴ | 2,140 cm⁴ | +5.6% |
| Plastic modulus, minor (Wpl,z) | 356 cm³ | 339 cm³ | +5.0% |
| Radius of gyration, minor (iz) | 5.91 cm | 5.85 cm | +1.0% |
| Torsion constant (It) | 4,410 cm⁴ | 4,430 cm⁴ | -0.5% |
RHS 200×150×10 to BS EN 10210-2:2006; CF RHS 200×150×10 to BS EN 10219-2:2006. Difference is expressed relative to CF RHS 200×150×10.
How to choose between them
On stiffness, RHS 200×150×10 has the larger second moment of area: 3,570 cm⁴ against 3,350 cm⁴, a difference of 6.6%. 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 (8.5 against 8.4 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, RHS 200×150×10 is the stronger section and CF RHS 200×150×10 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.