UB 457×191×98 vs H-450x200x11x19
UB 457×191×98 is an UB section from the UK Blue Book (SCI P363); H-450x200x11x19 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 2230 cm³ against 2240 cm³ of plastic modulus, a difference of 0.4%. They weigh essentially the same, 98.3 kg/m and 98.9 kg/m. Both are about 464 mm deep, so either fits the same construction zone.
| Property | UB 457×191×98 UB | H-450x200x11x19 MB & MC | Difference |
|---|---|---|---|
| Mass | 98.3 kg/m | 98.9 kg/m | -0.6% |
| Depth | 467.2 mm | 460 mm | +1.6% |
| Width | 192.8 mm | 202 mm | -4.6% |
| Web thickness | 11.4 mm | 11 mm | +3.6% |
| Flange thickness | 19.6 mm | 19 mm | +3.2% |
| Area | 125 cm² | 126 cm² | -0.8% |
| Second moment, major (Iy) | 45,700 cm⁴ | 45,430 cm⁴ | +0.6% |
| Plastic modulus, major (Wpl,y) | 2,230 cm³ | 2,240 cm³ | -0.4% |
| Elastic modulus, major (Wel,y) | 1,960 cm³ | 1,975 cm³ | -0.8% |
| Second moment, minor (Iz) | 2,350 cm⁴ | 2,619 cm⁴ | -10.3% |
| Plastic modulus, minor (Wpl,z) | 379 cm³ | 403 cm³ | -6.0% |
| Radius of gyration, minor (iz) | 4.33 cm | 4.56 cm | -5.0% |
| Torsion constant (It) | 121 cm⁴ | 126 cm⁴ | -4.0% |
UB 457×191×98 to BS EN 10365:2017; H-450x200x11x19 to Continental Steel. Difference is expressed relative to H-450x200x11x19.
How to choose between them
On stiffness, UB 457×191×98 has the larger second moment of area: 45,700 cm⁴ against 45,430 cm⁴, a difference of 0.6%. 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, the two are equally efficient (22.7 against 22.6 cm³ per kg/m), so on a pure steel-tonnage basis there is nothing to choose between them. The decision comes down to availability, connection detailing and what the rest of the frame uses.
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 MB & MC to 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.