SHS 200×200×6.3 vs CF SHS 200×200×6.3
SHS 200×200×6.3 is an SHS Hot-finished section from the UK Blue Book (SCI P363); CF SHS 200×200×6.3 is the closest equivalent in the UK Blue Book (SCI P363). SHS 200×200×6.3 carries more bending: 350 cm³ of plastic modulus against 341 cm³, 2.6% more. CF SHS 200×200×6.3 is the lighter of the two at 37.2 kg/m against 38 kg/m, a saving of 2.2% on steel weight. Both are about 200 mm deep, so either fits the same construction zone.
| Property | SHS 200×200×6.3 SHS Hot-finished | CF SHS 200×200×6.3 SHS Cold-formed | Difference |
|---|---|---|---|
| Mass | 38 kg/m | 37.2 kg/m | +2.2% |
| Depth | 200 mm | 200 mm | same |
| Width | 200 mm | 200 mm | same |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 48.4 cm² | 47.4 cm² | +2.1% |
| Second moment, major (Iy) | 3,010 cm⁴ | 2,920 cm⁴ | +3.1% |
| Plastic modulus, major (Wpl,y) | 350 cm³ | 341 cm³ | +2.6% |
| Elastic modulus, major (Wel,y) | 301 cm³ | 292 cm³ | +3.1% |
| Second moment, minor (Iz) | 3,010 cm⁴ | 2,920 cm⁴ | +3.1% |
| Plastic modulus, minor (Wpl,z) | 350 cm³ | 341 cm³ | +2.6% |
| Radius of gyration, minor (iz) | 7.89 cm | 7.85 cm | +0.5% |
| Torsion constant (It) | 4,650 cm⁴ | 4,680 cm⁴ | -0.6% |
SHS 200×200×6.3 to BS EN 10210-2:2006; CF SHS 200×200×6.3 to BS EN 10219-2:2006. Difference is expressed relative to CF SHS 200×200×6.3.
How to choose between them
On stiffness, SHS 200×200×6.3 has the larger second moment of area: 3,010 cm⁴ against 2,920 cm⁴, a difference of 3.1%. 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 (9.2 against 9.2 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, SHS 200×200×6.3 is the stronger section and CF SHS 200×200×6.3 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.