UC 203×203×127 vs HE 240 C
UC 203×203×127 is an UC section from the UK Blue Book (SCI P363); HE 240 C is the closest equivalent in the European (Continental) range. HE 240 C carries more bending: 1560 cm³ of plastic modulus against 1520 cm³, 2.6% more. HE 240 C is the lighter of the two at 119 kg/m against 127.5 kg/m, a saving of 7.1% on steel weight. HE 240 C is deeper, 255 mm against 241.4 mm, which matters where the floor zone is tight.
| Property | UC 203×203×127 UC | HE 240 C HE | Difference |
|---|---|---|---|
| Mass | 127.5 kg/m | 119 kg/m | +7.1% |
| Depth | 241.4 mm | 255 mm | -5.3% |
| Width | 213.9 mm | 244 mm | -12.3% |
| Web thickness | 18.1 mm | 14 mm | +29.3% |
| Flange thickness | 30.1 mm | 24.5 mm | +22.9% |
| Area | 162 cm² | 152 cm² | +6.6% |
| Second moment, major (Iy) | 15,400 cm⁴ | 17,300 cm⁴ | -11.0% |
| Plastic modulus, major (Wpl,y) | 1,520 cm³ | 1,560 cm³ | -2.6% |
| Elastic modulus, major (Wel,y) | 1,280 cm³ | 1,360 cm³ | -5.9% |
| Second moment, minor (Iz) | 4,920 cm⁴ | 5,940 cm⁴ | -17.2% |
| Plastic modulus, minor (Wpl,z) | 704 cm³ | 744 cm³ | -5.4% |
| Radius of gyration, minor (iz) | 5.5 cm | 6.25 cm | -12.0% |
| Torsion constant (It) | 427 cm⁴ | 289 cm⁴ | +47.8% |
UC 203×203×127 to BS EN 10365:2017; HE 240 C to EN 10365 · Continental Steel. Difference is expressed relative to HE 240 C.
How to choose between them
On stiffness, HE 240 C has the larger second moment of area: 17,300 cm⁴ against 15,400 cm⁴, a difference of 11.0%. 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, HE 240 C is the more efficient section: 13.1 against 11.9 cm³ per kg/m, 9.1% 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 7.1% weight.
In short, HE 240 C is the stronger section and HE 240 C 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.