W 18X76 vs H-500x300x11x15-111
W 18X76 is an W section from the American AISC Shapes Database; H-500x300x11x15-111 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 2671.1 cm³ against 2696 cm³ of plastic modulus, a difference of 0.9%. They weigh essentially the same, 113.1 kg/m and 111 kg/m. H-500x300x11x15-111 is deeper, 482 mm against 462.3 mm, which matters where the floor zone is tight.
| Property | W 18X76 W | H-500x300x11x15-111 MB & MC | Difference |
|---|---|---|---|
| Mass | 113.1 kg/m | 111 kg/m | +1.9% |
| Depth | 462.3 mm | 482 mm | -4.1% |
| Width | 279.4 mm | 300 mm | -6.9% |
| Web thickness | 10.8 mm | 11 mm | -1.8% |
| Flange thickness | 17.3 mm | 15 mm | +15.3% |
| Area | 143.9 cm² | 141 cm² | +2.1% |
| Second moment, major (Iy) | 55,359 cm⁴ | 58,270 cm⁴ | -5.0% |
| Plastic modulus, major (Wpl,y) | 2,671.1 cm³ | 2,696 cm³ | -0.9% |
| Elastic modulus, major (Wel,y) | 2,392.5 cm³ | 2,418 cm³ | -1.1% |
| Second moment, minor (Iz) | 6,327 cm⁴ | 6,756 cm⁴ | -6.3% |
| Plastic modulus, minor (Wpl,z) | 691.53 cm³ | 690 cm³ | +0.2% |
| Radius of gyration, minor (iz) | 6.63 cm | 6.92 cm | -4.2% |
| Torsion constant (It) | 117.8 cm⁴ | 93.9 cm⁴ | +25.5% |
W 18X76 to AISC Shapes Database v16.0; H-500x300x11x15-111 to Continental Steel. Difference is expressed relative to H-500x300x11x15-111.
How to choose between them
On stiffness, H-500x300x11x15-111 has the larger second moment of area: 58,270 cm⁴ against 55,359 cm⁴, a difference of 5.0%. 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-500x300x11x15-111 is the more efficient section: 24.3 against 23.6 cm³ per kg/m, 2.8% 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. W sections are specified to AISC Shapes Database v16.0 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.