WT 5X30 vs Tee 254×127×45
WT 5X30 is an WT section from the American AISC Shapes Database; Tee 254×127×45 is the closest equivalent in the UK Blue Book (SCI P363). WT 5X30 carries more bending: 96.192 cm³ of plastic modulus against 94 cm³, 2.3% more. They weigh essentially the same, 44.6 kg/m and 44.4 kg/m. Both are about 130 mm deep, so either fits the same construction zone.
| Property | WT 5X30 WT | Tee 254×127×45 Tees (from UC) | Difference |
|---|---|---|---|
| Mass | 44.6 kg/m | 44.4 kg/m | +0.5% |
| Depth | 129.8 mm | 130.1 mm | -0.2% |
| Width | 256.5 mm | 256.3 mm | +0.1% |
| Web thickness | 10.7 mm | 10.3 mm | +3.9% |
| Flange thickness | 17.3 mm | 17.3 mm | same |
| Area | 57 cm² | 56.7 cm² | +0.5% |
| Second moment, major (Iy) | 536.9 cm⁴ | 524 cm⁴ | +2.5% |
| Plastic modulus, major (Wpl,y) | 96.192 cm³ | 94 cm³ | +2.3% |
| Elastic modulus, major (Wel,y) | 49.817 cm³ | 48.5 cm³ | +2.7% |
| Second moment, minor (Iz) | 2,418 cm⁴ | 2,430 cm⁴ | -0.5% |
| Plastic modulus, minor (Wpl,z) | 286.77 cm³ | 288 cm³ | -0.4% |
| Radius of gyration, minor (iz) | 6.53 cm | 6.55 cm | -0.3% |
| Torsion constant (It) | 51.2 cm⁴ | 51.1 cm⁴ | +0.2% |
WT 5X30 to AISC Shapes Database v16.0; Tee 254×127×45 to BS EN 10365:2017. Difference is expressed relative to Tee 254×127×45.
How to choose between them
On stiffness, WT 5X30 has the larger second moment of area: 536.9 cm⁴ against 524 cm⁴, a difference of 2.5%. 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 (2.2 against 2.1 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.
These come from different catalogues, so treat the swap as a design change rather than a like-for-like substitution. WT sections are specified to AISC Shapes Database v16.0 and Tees (from UC) to BS EN 10365:2017; 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, WT 5X30 is the stronger section and Tee 254×127×45 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.