UB 610×178×82 vs H-600x200x8x13
UB 610×178×82 is an UB section from the UK Blue Book (SCI P363); H-600x200x8x13 is the closest equivalent in the European (Continental) range. H-600x200x8x13 carries more bending: 2239 cm³ of plastic modulus against 2190 cm³, 2.2% more. H-600x200x8x13 is the lighter of the two at 79 kg/m against 81.8 kg/m, a saving of 3.5% on steel weight. Both are about 595 mm deep, so either fits the same construction zone.
| Property | UB 610×178×82 UB | H-600x200x8x13 MB & MC | Difference |
|---|---|---|---|
| Mass | 81.8 kg/m | 79 kg/m | +3.5% |
| Depth | 598.6 mm | 592 mm | +1.1% |
| Width | 177.9 mm | 197 mm | -9.7% |
| Web thickness | 10 mm | 8 mm | +25.0% |
| Flange thickness | 12.8 mm | 13 mm | -1.5% |
| Area | 104 cm² | 101 cm² | +3.0% |
| Second moment, major (Iy) | 55,900 cm⁴ | 58,240 cm⁴ | -4.0% |
| Plastic modulus, major (Wpl,y) | 2,190 cm³ | 2,239 cm³ | -2.2% |
| Elastic modulus, major (Wel,y) | 1,870 cm³ | 1,968 cm³ | -5.0% |
| Second moment, minor (Iz) | 1,210 cm⁴ | 1,665 cm⁴ | -27.3% |
| Plastic modulus, minor (Wpl,z) | 218 cm³ | 265 cm³ | -17.7% |
| Radius of gyration, minor (iz) | 3.4 cm | 4.07 cm | -16.5% |
| Torsion constant (It) | 48.8 cm⁴ | 53 cm⁴ | -7.9% |
UB 610×178×82 to BS EN 10365:2017; H-600x200x8x13 to Continental Steel. Difference is expressed relative to H-600x200x8x13.
How to choose between them
On stiffness, H-600x200x8x13 has the larger second moment of area: 58,240 cm⁴ against 55,900 cm⁴, a difference of 4.0%. 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, H-600x200x8x13 is the more efficient section: 28.3 against 26.8 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: H-600x200x8x13 has 265 cm³ of minor-axis plastic modulus against 218 cm³, 17.7% 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 3.5% weight.
In short, H-600x200x8x13 is the stronger section and H-600x200x8x13 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.