Tee 146×127×16 vs WT 5X7.5
Tee 146×127×16 is an Tees (from UB) section from the UK Blue Book (SCI P363); WT 5X7.5 is the closest equivalent in the American AISC Shapes Database. Tee 146×127×16 carries more bending: 46 cm³ of plastic modulus against 44.409 cm³, 3.6% more. WT 5X7.5 is the lighter of the two at 11.2 kg/m against 15.5 kg/m, a saving of 38.4% on steel weight. Both are about 126 mm deep, so either fits the same construction zone.
| Property | Tee 146×127×16 Tees (from UB) | WT 5X7.5 WT | Difference |
|---|---|---|---|
| Mass | 15.5 kg/m | 11.2 kg/m | +38.4% |
| Depth | 125.6 mm | 127 mm | -1.1% |
| Width | 146.1 mm | 101.6 mm | +43.8% |
| Web thickness | 6 mm | 5.8 mm | +3.4% |
| Flange thickness | 8.6 mm | 6.9 mm | +24.6% |
| Area | 19.8 cm² | 14.3 cm² | +38.5% |
| Second moment, major (Iy) | 259 cm⁴ | 226.8 cm⁴ | +14.2% |
| Plastic modulus, major (Wpl,y) | 46 cm³ | 44.409 cm³ | +3.6% |
| Elastic modulus, major (Wel,y) | 26.2 cm³ | 24.581 cm³ | +6.6% |
| Second moment, minor (Iz) | 224 cm⁴ | 60.35 cm⁴ | +271.2% |
| Plastic modulus, minor (Wpl,z) | 47.1 cm³ | 18.845 cm³ | +149.9% |
| Radius of gyration, minor (iz) | 3.36 cm | 2.06 cm | +63.1% |
| Torsion constant (It) | 4.26 cm⁴ | 2.16 cm⁴ | +97.2% |
Tee 146×127×16 to BS EN 10365:2017; WT 5X7.5 to AISC Shapes Database v16.0. Difference is expressed relative to WT 5X7.5.
How to choose between them
On stiffness, Tee 146×127×16 has the larger second moment of area: 259 cm⁴ against 226.8 cm⁴, a difference of 14.2%. 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 of steel, WT 5X7.5 is the more efficient section: 4.0 against 3.0 cm³ per kg/m, 25.2% 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: Tee 146×127×16 has 47.1 cm³ of minor-axis plastic modulus against 18.845 cm³, 149.9% 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 38.4% weight.
In short, Tee 146×127×16 is the stronger section and WT 5X7.5 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.