WT 10.5X55.5 vs Tee 210×267×69
WT 10.5X55.5 is an WT section from the American AISC Shapes Database; Tee 210×267×69 is the closest equivalent in the UK Blue Book (SCI P363). Tee 210×267×69 carries more bending: 520 cm³ of plastic modulus against 508 cm³, 2.3% more. Tee 210×267×69 is the lighter of the two at 69.1 kg/m against 82.6 kg/m, a saving of 19.5% on steel weight. Both are about 274 mm deep, so either fits the same construction zone.
| Property | WT 10.5X55.5 WT | Tee 210×267×69 Tees (from UB) | Difference |
|---|---|---|---|
| Mass | 82.6 kg/m | 69.1 kg/m | +19.5% |
| Depth | 274.3 mm | 274.5 mm | -0.1% |
| Width | 312.4 mm | 213.9 mm | +46.0% |
| Web thickness | 14 mm | 14.7 mm | -4.8% |
| Flange thickness | 22.2 mm | 23.6 mm | -5.9% |
| Area | 105.2 cm² | 88.1 cm² | +19.4% |
| Second moment, major (Iy) | 6,243 cm⁴ | 5,990 cm⁴ | +4.2% |
| Plastic modulus, major (Wpl,y) | 508 cm³ | 520 cm³ | -2.3% |
| Elastic modulus, major (Wel,y) | 286.77 cm³ | 292 cm³ | -1.8% |
| Second moment, minor (Iz) | 5,702 cm⁴ | 1,930 cm⁴ | +195.4% |
| Plastic modulus, minor (Wpl,z) | 558.8 cm³ | 284 cm³ | +96.8% |
| Radius of gyration, minor (iz) | 7.37 cm | 4.68 cm | +57.5% |
| Torsion constant (It) | 141.5 cm⁴ | 125 cm⁴ | +13.2% |
WT 10.5X55.5 to AISC Shapes Database v16.0; Tee 210×267×69 to BS EN 10365:2017. Difference is expressed relative to Tee 210×267×69.
How to choose between them
On stiffness, WT 10.5X55.5 has the larger second moment of area: 6,243 cm⁴ against 5,990 cm⁴, a difference of 4.2%. 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, Tee 210×267×69 is the more efficient section: 7.5 against 6.2 cm³ per kg/m, 18.3% 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 10.5X55.5 has 558.8 cm³ of minor-axis plastic modulus against 284 cm³, 96.8% 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 19.5% weight.
In short, Tee 210×267×69 is the stronger section and Tee 210×267×69 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.