UB 610×305×238 vs W 24X162
UB 610×305×238 is an UB section from the UK Blue Book (SCI P363); W 24X162 is the closest equivalent in the American AISC Shapes Database. W 24X162 carries more bending: 7669.1 cm³ of plastic modulus against 7490 cm³, 2.3% more. They weigh essentially the same, 238.1 kg/m and 241.1 kg/m. Both are about 635 mm deep, so either fits the same construction zone.
| Property | UB 610×305×238 UB | W 24X162 W | Difference |
|---|---|---|---|
| Mass | 238.1 kg/m | 241.1 kg/m | -1.2% |
| Depth | 635.8 mm | 635 mm | +0.1% |
| Width | 311.4 mm | 330.2 mm | -5.7% |
| Web thickness | 18.4 mm | 17.9 mm | +2.8% |
| Flange thickness | 31.4 mm | 31 mm | +1.3% |
| Area | 303 cm² | 308.4 cm² | -1.8% |
| Second moment, major (Iy) | 209,000 cm⁴ | 215,192 cm⁴ | -2.9% |
| Plastic modulus, major (Wpl,y) | 7,490 cm³ | 7,669.1 cm³ | -2.3% |
| Elastic modulus, major (Wel,y) | 6,590 cm³ | 6,784.2 cm³ | -2.9% |
| Second moment, minor (Iz) | 15,800 cm⁴ | 18,439 cm⁴ | -14.3% |
| Plastic modulus, minor (Wpl,z) | 1,570 cm³ | 1,720.6 cm³ | -8.8% |
| Radius of gyration, minor (iz) | 7.23 cm | 7.75 cm | -6.7% |
| Torsion constant (It) | 785 cm⁴ | 770 cm⁴ | +1.9% |
UB 610×305×238 to BS EN 10365:2017; W 24X162 to AISC Shapes Database v16.0. Difference is expressed relative to W 24X162.
How to choose between them
On stiffness, W 24X162 has the larger second moment of area: 215,192 cm⁴ against 209,000 cm⁴, a difference of 2.9%. 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 (31.5 against 31.8 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.
The two diverge much more about the minor axis: W 24X162 has 1720.6 cm³ of minor-axis plastic modulus against 1570 cm³, 8.8% more. If the member sees any minor-axis bending, or if it is unrestrained over a long length and lateral-torsional buckling governs, that gap decides the comparison even though the major-axis numbers looked equivalent.
These come from different catalogues, so treat the swap as a design change rather than a like-for-like substitution. UB sections are specified to BS EN 10365:2017 and W to AISC Shapes Database v16.0; the steel grades, tolerances and available lengths differ, connection details and bolt gauges are set out differently, and the two are rarely both stocked in the same market. Check availability before changing a section on a drawing to save a marginal amount of weight.
In short, W 24X162 is the stronger section and UB 610×305×238 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.