WT 6X13 vs Tee 102×152×14
WT 6X13 is an WT section from the American AISC Shapes Database; Tee 102×152×14 is the closest equivalent in the UK Blue Book (SCI P363). They are close to interchangeable in bending: 68.826 cm³ against 67.5 cm³ of plastic modulus, a difference of 2.0%. Tee 102×152×14 is the lighter of the two at 14.1 kg/m against 19.3 kg/m, a saving of 36.9% on steel weight. Both are about 155 mm deep, so either fits the same construction zone.
| Property | WT 6X13 WT | Tee 102×152×14 Tees (from UB) | Difference |
|---|---|---|---|
| Mass | 19.3 kg/m | 14.1 kg/m | +36.9% |
| Depth | 155.2 mm | 154.3 mm | +0.6% |
| Width | 164.8 mm | 101.8 mm | +61.9% |
| Web thickness | 5.8 mm | 6 mm | -3.3% |
| Flange thickness | 9.7 mm | 8.8 mm | +10.2% |
| Area | 24.6 cm² | 17.9 cm² | +37.4% |
| Second moment, major (Iy) | 487 cm⁴ | 420 cm⁴ | +16.0% |
| Plastic modulus, major (Wpl,y) | 68.826 cm³ | 67.5 cm³ | +2.0% |
| Elastic modulus, major (Wel,y) | 39.329 cm³ | 37.4 cm³ | +5.2% |
| Second moment, minor (Iz) | 360.5 cm⁴ | 77.7 cm⁴ | +364.0% |
| Plastic modulus, minor (Wpl,z) | 66.859 cm³ | 24.2 cm³ | +176.3% |
| Radius of gyration, minor (iz) | 3.84 cm | 2.08 cm | +84.6% |
| Torsion constant (It) | 6.24 cm⁴ | 3.69 cm⁴ | +69.1% |
WT 6X13 to AISC Shapes Database v16.0; Tee 102×152×14 to BS EN 10365:2017. Difference is expressed relative to Tee 102×152×14.
How to choose between them
On stiffness, WT 6X13 has the larger second moment of area: 487 cm⁴ against 420 cm⁴, a difference of 16.0%. 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 102×152×14 is the more efficient section: 4.8 against 3.6 cm³ per kg/m, 25.5% 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 6X13 has 66.859 cm³ of minor-axis plastic modulus against 24.2 cm³, 176.3% 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. WT sections are specified to AISC Shapes Database v16.0 and Tees (from UB) 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 36.9% weight.
In short, WT 6X13 is the stronger section and Tee 102×152×14 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.