Tee 165×152×20 vs WT 6X9.5
Tee 165×152×20 is an Tees (from UB) section from the UK Blue Book (SCI P363); WT 6X9.5 is the closest equivalent in the American AISC Shapes Database. They are close to interchangeable in bending: 67.6 cm³ against 67.351 cm³ of plastic modulus, a difference of 0.4%. WT 6X9.5 is the lighter of the two at 14.1 kg/m against 20.1 kg/m, a saving of 42.6% on steel weight. Both are about 153 mm deep, so either fits the same construction zone.
| Property | Tee 165×152×20 Tees (from UB) | WT 6X9.5 WT | Difference |
|---|---|---|---|
| Mass | 20.1 kg/m | 14.1 kg/m | +42.6% |
| Depth | 151.6 mm | 154.4 mm | -1.8% |
| Width | 165 mm | 101.9 mm | +61.9% |
| Web thickness | 6 mm | 6 mm | same |
| Flange thickness | 10.2 mm | 8.9 mm | +14.6% |
| Area | 25.7 cm² | 18 cm² | +42.8% |
| Second moment, major (Iy) | 468 cm⁴ | 420.4 cm⁴ | +11.3% |
| Plastic modulus, major (Wpl,y) | 67.6 cm³ | 67.351 cm³ | +0.4% |
| Elastic modulus, major (Wel,y) | 38.6 cm³ | 37.363 cm³ | +3.3% |
| Second moment, minor (Iz) | 382 cm⁴ | 78.25 cm⁴ | +388.2% |
| Plastic modulus, minor (Wpl,z) | 70.9 cm³ | 24.417 cm³ | +190.4% |
| Radius of gyration, minor (iz) | 3.86 cm | 2.09 cm | +84.7% |
| Torsion constant (It) | 7.35 cm⁴ | 3.74 cm⁴ | +96.5% |
Tee 165×152×20 to BS EN 10365:2017; WT 6X9.5 to AISC Shapes Database v16.0. Difference is expressed relative to WT 6X9.5.
How to choose between them
On stiffness, Tee 165×152×20 has the larger second moment of area: 468 cm⁴ against 420.4 cm⁴, a difference of 11.3%. 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 6X9.5 is the more efficient section: 4.8 against 3.4 cm³ per kg/m, 29.6% 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 165×152×20 has 70.9 cm³ of minor-axis plastic modulus against 24.417 cm³, 190.4% 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 42.6% weight.
In short, Tee 165×152×20 is the stronger section and WT 6X9.5 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.