UB 610×229×101 vs H-600x200x11x17-103
UB 610×229×101 is an UB section from the UK Blue Book (SCI P363); H-600x200x11x17-103 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 2880 cm³ against 2904 cm³ of plastic modulus, a difference of 0.8%. They weigh essentially the same, 101.2 kg/m and 103 kg/m. Both are about 601 mm deep, so either fits the same construction zone.
| Property | UB 610×229×101 UB | H-600x200x11x17-103 MB & MC | Difference |
|---|---|---|---|
| Mass | 101.2 kg/m | 103 kg/m | -1.7% |
| Depth | 602.6 mm | 600 mm | +0.4% |
| Width | 227.6 mm | 200 mm | +13.8% |
| Web thickness | 10.5 mm | 11 mm | -4.5% |
| Flange thickness | 14.8 mm | 17 mm | -12.9% |
| Area | 129 cm² | 132 cm² | -2.3% |
| Second moment, major (Iy) | 75,800 cm⁴ | 75,560 cm⁴ | +0.3% |
| Plastic modulus, major (Wpl,y) | 2,880 cm³ | 2,904 cm³ | -0.8% |
| Elastic modulus, major (Wel,y) | 2,520 cm³ | 2,519 cm³ | same |
| Second moment, minor (Iz) | 2,910 cm⁴ | 2,274 cm⁴ | +28.0% |
| Plastic modulus, minor (Wpl,z) | 400 cm³ | 358 cm³ | +11.7% |
| Radius of gyration, minor (iz) | 4.75 cm | 4.16 cm | +14.2% |
| Torsion constant (It) | 77 cm⁴ | 97.3 cm⁴ | -20.9% |
UB 610×229×101 to BS EN 10365:2017; H-600x200x11x17-103 to Continental Steel. Difference is expressed relative to H-600x200x11x17-103.
How to choose between them
On stiffness, UB 610×229×101 has the larger second moment of area: 75,800 cm⁴ against 75,560 cm⁴, a difference of 0.3%. 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 (28.5 against 28.2 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.
The two diverge much more about the minor axis: UB 610×229×101 has 400 cm³ of minor-axis plastic modulus against 358 cm³, 11.7% 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 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.