UB 533×312×182 vs H-600x300x14x23-170
UB 533×312×182 is an UB section from the UK Blue Book (SCI P363); H-600x300x14x23-170 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 5040 cm³ against 5057 cm³ of plastic modulus, a difference of 0.3%. H-600x300x14x23-170 is the lighter of the two at 170 kg/m against 181.5 kg/m, a saving of 6.8% on steel weight. H-600x300x14x23-170 is deeper, 594 mm against 550.7 mm, which matters where the floor zone is tight.
| Property | UB 533×312×182 UB | H-600x300x14x23-170 MB & MC | Difference |
|---|---|---|---|
| Mass | 181.5 kg/m | 170 kg/m | +6.8% |
| Depth | 550.7 mm | 594 mm | -7.3% |
| Width | 314.5 mm | 302 mm | +4.1% |
| Web thickness | 15.2 mm | 14 mm | +8.6% |
| Flange thickness | 24.4 mm | 23 mm | +6.1% |
| Area | 231 cm² | 217 cm² | +6.5% |
| Second moment, major (Iy) | 123,000 cm⁴ | 133,600 cm⁴ | -7.9% |
| Plastic modulus, major (Wpl,y) | 5,040 cm³ | 5,057 cm³ | -0.3% |
| Elastic modulus, major (Wel,y) | 4,480 cm³ | 4,497 cm³ | -0.4% |
| Second moment, minor (Iz) | 12,700 cm⁴ | 10,570 cm⁴ | +20.2% |
| Plastic modulus, minor (Wpl,z) | 1,240 cm³ | 1,077 cm³ | +15.1% |
| Radius of gyration, minor (iz) | 7.4 cm | 6.98 cm | +6.0% |
| Torsion constant (It) | 373 cm⁴ | 304 cm⁴ | +22.7% |
UB 533×312×182 to BS EN 10365:2017; H-600x300x14x23-170 to Continental Steel. Difference is expressed relative to H-600x300x14x23-170.
How to choose between them
On stiffness, H-600x300x14x23-170 has the larger second moment of area: 133,600 cm⁴ against 123,000 cm⁴, a difference of 7.9%. 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, H-600x300x14x23-170 is the more efficient section: 29.7 against 27.8 cm³ per kg/m, 6.7% 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 533×312×182 has 1240 cm³ of minor-axis plastic modulus against 1077 cm³, 15.1% 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 6.8% weight.
In short, H-600x300x14x23-170 is the stronger section and H-600x300x14x23-170 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.