Tee 210×267×69 vs ST 10X43
Tee 210×267×69 is an Tees (from UB) section from the UK Blue Book (SCI P363); ST 10X43 is the closest equivalent in the American AISC Shapes Database. Tee 210×267×69 carries more bending: 520 cm³ of plastic modulus against 509.64 cm³, 2.0% more. ST 10X43 is the lighter of the two at 64 kg/m against 69.1 kg/m, a saving of 8.0% on steel weight. Tee 210×267×69 is deeper, 274.5 mm against 259.1 mm, which matters where the floor zone is tight.
| Property | Tee 210×267×69 Tees (from UB) | ST 10X43 ST | Difference |
|---|---|---|---|
| Mass | 69.1 kg/m | 64 kg/m | +8.0% |
| Depth | 274.5 mm | 259.1 mm | +5.9% |
| Width | 213.9 mm | 179.3 mm | +19.3% |
| Web thickness | 14.7 mm | 16.8 mm | -12.5% |
| Flange thickness | 23.6 mm | 23.4 mm | +0.9% |
| Area | 88.1 cm² | 81.9 cm² | +7.6% |
| Second moment, major (Iy) | 5,990 cm⁴ | 5,161 cm⁴ | +16.1% |
| Plastic modulus, major (Wpl,y) | 520 cm³ | 509.64 cm³ | +2.0% |
| Elastic modulus, major (Wel,y) | 292 cm³ | 281.86 cm³ | +3.6% |
| Second moment, minor (Iz) | 1,930 cm⁴ | 969.8 cm⁴ | +99.0% |
| Plastic modulus, minor (Wpl,z) | 284 cm³ | 190.09 cm³ | +49.4% |
| Radius of gyration, minor (iz) | 4.68 cm | 3.45 cm | +35.7% |
| Torsion constant (It) | 125 cm⁴ | 137.4 cm⁴ | -9.0% |
Tee 210×267×69 to BS EN 10365:2017; ST 10X43 to AISC Shapes Database v16.0. Difference is expressed relative to ST 10X43.
How to choose between them
On stiffness, Tee 210×267×69 has the larger second moment of area: 5,990 cm⁴ against 5,161 cm⁴, a difference of 16.1%. 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, ST 10X43 is the more efficient section: 8.0 against 7.5 cm³ per kg/m, 5.5% 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: Tee 210×267×69 has 284 cm³ of minor-axis plastic modulus against 190.09 cm³, 49.4% 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 ST 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 8.0% weight.
In short, Tee 210×267×69 is the stronger section and ST 10X43 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.