Tee 165×267×37 vs WT 10.5X27.5
Tee 165×267×37 is an Tees (from UB) section from the UK Blue Book (SCI P363); WT 10.5X27.5 is the closest equivalent in the American AISC Shapes Database. They are close to interchangeable in bending: 321 cm³ against 317.91 cm³ of plastic modulus, a difference of 1.0%. Tee 165×267×37 is the lighter of the two at 37.3 kg/m against 40.9 kg/m, a saving of 8.8% on steel weight. Both are about 264 mm deep, so either fits the same construction zone.
| Property | Tee 165×267×37 Tees (from UB) | WT 10.5X27.5 WT | Difference |
|---|---|---|---|
| Mass | 37.3 kg/m | 40.9 kg/m | -8.8% |
| Depth | 264.5 mm | 264.2 mm | +0.1% |
| Width | 165.9 mm | 208.8 mm | -20.5% |
| Web thickness | 9.7 mm | 9.5 mm | +2.1% |
| Flange thickness | 13.6 mm | 13.3 mm | +2.3% |
| Area | 47.6 cm² | 52.3 cm² | -9.0% |
| Second moment, major (Iy) | 3,350 cm⁴ | 3,513 cm⁴ | -4.6% |
| Plastic modulus, major (Wpl,y) | 321 cm³ | 317.91 cm³ | +1.0% |
| Elastic modulus, major (Wel,y) | 176 cm³ | 178.62 cm³ | -1.5% |
| Second moment, minor (Iz) | 520 cm⁴ | 1,007 cm⁴ | -48.4% |
| Plastic modulus, minor (Wpl,z) | 100 cm³ | 150.43 cm³ | -33.5% |
| Radius of gyration, minor (iz) | 3.3 cm | 4.39 cm | -24.8% |
| Torsion constant (It) | 23.9 cm⁴ | 25.68 cm⁴ | -6.9% |
Tee 165×267×37 to BS EN 10365:2017; WT 10.5X27.5 to AISC Shapes Database v16.0. Difference is expressed relative to WT 10.5X27.5.
How to choose between them
On stiffness, WT 10.5X27.5 has the larger second moment of area: 3,513 cm⁴ against 3,350 cm⁴, a difference of 4.6%. 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 of steel, Tee 165×267×37 is the more efficient section: 8.6 against 7.8 cm³ per kg/m, 10.7% better. Over a floor of repeated beams that difference is real tonnage, though it is often outweighed by whichever section the fabricator can actually source.
The two diverge much more about the minor axis: WT 10.5X27.5 has 150.43 cm³ of minor-axis plastic modulus against 100 cm³, 33.5% 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. Tees (from UB) sections are specified to BS EN 10365:2017 and WT 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 8.8% weight.
In short, Tee 165×267×37 is the stronger section and Tee 165×267×37 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.