Tee 191×229×67 vs WT 9X53
Tee 191×229×67 is an Tees (from UB) section from the UK Blue Book (SCI P363); WT 9X53 is the closest equivalent in the American AISC Shapes Database. They are close to interchangeable in bending: 414 cm³ against 412.95 cm³ of plastic modulus, a difference of 0.3%. Tee 191×229×67 is the lighter of the two at 66.6 kg/m against 78.9 kg/m, a saving of 15.6% on steel weight. Both are about 239 mm deep, so either fits the same construction zone.
| Property | Tee 191×229×67 Tees (from UB) | WT 9X53 WT | Difference |
|---|---|---|---|
| Mass | 66.6 kg/m | 78.9 kg/m | -15.6% |
| Depth | 240.3 mm | 238 mm | +1.0% |
| Width | 196.7 mm | 284.5 mm | -30.9% |
| Web thickness | 15.3 mm | 15 mm | +2.0% |
| Flange thickness | 26.3 mm | 23.9 mm | +10.0% |
| Area | 84.9 cm² | 100.6 cm² | -15.6% |
| Second moment, major (Iy) | 4,180 cm⁴ | 4,329 cm⁴ | -3.4% |
| Plastic modulus, major (Wpl,y) | 414 cm³ | 412.95 cm³ | +0.3% |
| Elastic modulus, major (Wel,y) | 231 cm³ | 231.06 cm³ | same |
| Second moment, minor (Iz) | 1,670 cm⁴ | 4,579 cm⁴ | -63.5% |
| Plastic modulus, minor (Wpl,z) | 267 cm³ | 494.89 cm³ | -46.0% |
| Radius of gyration, minor (iz) | 4.44 cm | 6.76 cm | -34.3% |
| Torsion constant (It) | 146 cm⁴ | 155.3 cm⁴ | -6.0% |
Tee 191×229×67 to BS EN 10365:2017; WT 9X53 to AISC Shapes Database v16.0. Difference is expressed relative to WT 9X53.
How to choose between them
On stiffness, WT 9X53 has the larger second moment of area: 4,329 cm⁴ against 4,180 cm⁴, a difference of 3.4%. 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 191×229×67 is the more efficient section: 6.2 against 5.2 cm³ per kg/m, 18.8% 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 9X53 has 494.89 cm³ of minor-axis plastic modulus against 267 cm³, 46.0% 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 15.6% weight.
In short, Tee 191×229×67 is the stronger section and Tee 191×229×67 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.