SHS 160×160×8 vs CF SHS 160×160×8
SHS 160×160×8 is an SHS Hot-finished section from the UK Blue Book (SCI P363); CF SHS 160×160×8 is the closest equivalent in the UK Blue Book (SCI P363). SHS 160×160×8 carries more bending: 272 cm³ of plastic modulus against 260 cm³, 4.6% more. CF SHS 160×160×8 is the lighter of the two at 36.5 kg/m against 37.6 kg/m, a saving of 3.0% on steel weight. Both are about 160 mm deep, so either fits the same construction zone.
| Property | SHS 160×160×8 SHS Hot-finished | CF SHS 160×160×8 SHS Cold-formed | Difference |
|---|---|---|---|
| Mass | 37.6 kg/m | 36.5 kg/m | +3.0% |
| Depth | 160 mm | 160 mm | same |
| Width | 160 mm | 160 mm | same |
| Web thickness | 0 mm | 0 mm | same |
| Flange thickness | 0 mm | 0 mm | same |
| Area | 48 cm² | 46.4 cm² | +3.4% |
| Second moment, major (Iy) | 1,830 cm⁴ | 1,740 cm⁴ | +5.2% |
| Plastic modulus, major (Wpl,y) | 272 cm³ | 260 cm³ | +4.6% |
| Elastic modulus, major (Wel,y) | 229 cm³ | 218 cm³ | +5.0% |
| Second moment, minor (Iz) | 1,830 cm⁴ | 1,740 cm⁴ | +5.2% |
| Plastic modulus, minor (Wpl,z) | 272 cm³ | 260 cm³ | +4.6% |
| Radius of gyration, minor (iz) | 6.18 cm | 6.12 cm | +1.0% |
| Torsion constant (It) | 2,880 cm⁴ | 2,900 cm⁴ | -0.7% |
SHS 160×160×8 to BS EN 10210-2:2006; CF SHS 160×160×8 to BS EN 10219-2:2006. Difference is expressed relative to CF SHS 160×160×8.
How to choose between them
On stiffness, SHS 160×160×8 has the larger second moment of area: 1,830 cm⁴ against 1,740 cm⁴, a difference of 5.2%. 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 (7.2 against 7.1 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 160×160×8 is the stronger section and CF SHS 160×160×8 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.