UB 457×191×106 vs IPE V 450
UB 457×191×106 is an UB section from the UK Blue Book (SCI P363); IPE V 450 is the closest equivalent in the European (Continental) range. UB 457×191×106 carries more bending: 2390 cm³ of plastic modulus against 2300 cm³, 3.9% more. They weigh essentially the same, 105.8 kg/m and 107 kg/m. Both are about 465 mm deep, so either fits the same construction zone.
| Property | UB 457×191×106 UB | IPE V 450 IPE | Difference |
|---|---|---|---|
| Mass | 105.8 kg/m | 107 kg/m | -1.1% |
| Depth | 469.2 mm | 460 mm | +2.0% |
| Width | 194 mm | 194 mm | same |
| Web thickness | 12.6 mm | 12.4 mm | +1.6% |
| Flange thickness | 20.6 mm | 19.6 mm | +5.1% |
| Area | 135 cm² | 132 cm² | +2.3% |
| Second moment, major (Iy) | 48,900 cm⁴ | 46,200 cm⁴ | +5.8% |
| Plastic modulus, major (Wpl,y) | 2,390 cm³ | 2,300 cm³ | +3.9% |
| Elastic modulus, major (Wel,y) | 2,080 cm³ | 2,010 cm³ | +3.5% |
| Second moment, minor (Iz) | 2,510 cm⁴ | 2,400 cm⁴ | +4.6% |
| Plastic modulus, minor (Wpl,z) | 405 cm³ | 389 cm³ | +4.1% |
| Radius of gyration, minor (iz) | 4.32 cm | 4.26 cm | +1.4% |
| Torsion constant (It) | 146 cm⁴ | 149 cm⁴ | -2.0% |
UB 457×191×106 to BS EN 10365:2017; IPE V 450 to EN 10365 · Continental Steel. Difference is expressed relative to IPE V 450.
How to choose between them
On stiffness, UB 457×191×106 has the larger second moment of area: 48,900 cm⁴ against 46,200 cm⁴, a difference of 5.8%. 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, UB 457×191×106 is the more efficient section: 22.6 against 21.5 cm³ per kg/m, 5.1% 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.
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, UB 457×191×106 is the stronger section and UB 457×191×106 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.