UB 254×146×43 vs IPE O 270
UB 254×146×43 is an UB section from the UK Blue Book (SCI P363); IPE O 270 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 566 cm³ against 575 cm³ of plastic modulus, a difference of 1.6%. They weigh essentially the same, 43 kg/m and 42.3 kg/m. IPE O 270 is deeper, 274 mm against 259.6 mm, which matters where the floor zone is tight.
| Property | UB 254×146×43 UB | IPE O 270 IPE | Difference |
|---|---|---|---|
| Mass | 43 kg/m | 42.3 kg/m | +1.7% |
| Depth | 259.6 mm | 274 mm | -5.3% |
| Width | 147.3 mm | 136 mm | +8.3% |
| Web thickness | 7.2 mm | 7.5 mm | -4.0% |
| Flange thickness | 12.7 mm | 12.2 mm | +4.1% |
| Area | 54.8 cm² | 53.8 cm² | +1.9% |
| Second moment, major (Iy) | 6,540 cm⁴ | 6,950 cm⁴ | -5.9% |
| Plastic modulus, major (Wpl,y) | 566 cm³ | 575 cm³ | -1.6% |
| Elastic modulus, major (Wel,y) | 504 cm³ | 507 cm³ | -0.6% |
| Second moment, minor (Iz) | 677 cm⁴ | 514 cm⁴ | +31.7% |
| Plastic modulus, minor (Wpl,z) | 141 cm³ | 118 cm³ | +19.5% |
| Radius of gyration, minor (iz) | 3.52 cm | 3.09 cm | +13.9% |
| Torsion constant (It) | 23.9 cm⁴ | 25 cm⁴ | -4.4% |
UB 254×146×43 to BS EN 10365:2017; IPE O 270 to EN 10365 · Continental Steel. Difference is expressed relative to IPE O 270.
How to choose between them
On stiffness, IPE O 270 has the larger second moment of area: 6,950 cm⁴ against 6,540 cm⁴, a difference of 5.9%. 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, IPE O 270 is the more efficient section: 13.6 against 13.2 cm³ per kg/m, 3.2% 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: UB 254×146×43 has 141 cm³ of minor-axis plastic modulus against 118 cm³, 19.5% 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. UB sections are specified to BS EN 10365:2017 and IPE to EN 10365 · Continental Steel; 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 a marginal amount of weight.
In short, these two are genuine equivalents. Pick whichever your supplier stocks and the rest of the frame already uses.