UC 203×203×60 vs HE 200 B
UC 203×203×60 is an UC section from the UK Blue Book (SCI P363); HE 200 B is the closest equivalent in the European (Continental) range. UC 203×203×60 carries more bending: 656 cm³ of plastic modulus against 642 cm³, 2.2% more. UC 203×203×60 is the lighter of the two at 60 kg/m against 61.3 kg/m, a saving of 2.1% on steel weight. UC 203×203×60 is deeper, 209.6 mm against 200 mm, which matters where the floor zone is tight.
| Property | UC 203×203×60 UC | HE 200 B HE | Difference |
|---|---|---|---|
| Mass | 60 kg/m | 61.3 kg/m | -2.1% |
| Depth | 209.6 mm | 200 mm | +4.8% |
| Width | 205.8 mm | 200 mm | +2.9% |
| Web thickness | 9.4 mm | 9 mm | +4.4% |
| Flange thickness | 14.2 mm | 15 mm | -5.3% |
| Area | 76.4 cm² | 78.1 cm² | -2.2% |
| Second moment, major (Iy) | 6,120 cm⁴ | 5,700 cm⁴ | +7.4% |
| Plastic modulus, major (Wpl,y) | 656 cm³ | 642 cm³ | +2.2% |
| Elastic modulus, major (Wel,y) | 584 cm³ | 570 cm³ | +2.5% |
| Second moment, minor (Iz) | 2,060 cm⁴ | 2,000 cm⁴ | +3.0% |
| Plastic modulus, minor (Wpl,z) | 305 cm³ | 306 cm³ | -0.3% |
| Radius of gyration, minor (iz) | 5.2 cm | 5.07 cm | +2.6% |
| Torsion constant (It) | 47.2 cm⁴ | 59.7 cm⁴ | -20.9% |
UC 203×203×60 to BS EN 10365:2017; HE 200 B to EN 10365 · Continental Steel. Difference is expressed relative to HE 200 B.
How to choose between them
On stiffness, UC 203×203×60 has the larger second moment of area: 6,120 cm⁴ against 5,700 cm⁴, a difference of 7.4%. 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, UC 203×203×60 is the more efficient section: 10.9 against 10.5 cm³ per kg/m, 4.4% 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. UC sections are specified to BS EN 10365:2017 and HE 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 2.1% weight.
In short, UC 203×203×60 is the stronger section and UC 203×203×60 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.