W 18X76 vs HE 500 AA
W 18X76 is an W section from the American AISC Shapes Database; HE 500 AA is the closest equivalent in the European (Continental) range. W 18X76 carries more bending: 2671.1 cm³ of plastic modulus against 2580 cm³, 3.5% more. HE 500 AA is the lighter of the two at 107 kg/m against 113.1 kg/m, a saving of 5.7% on steel weight. HE 500 AA is deeper, 472 mm against 462.3 mm, which matters where the floor zone is tight.
| Property | W 18X76 W | HE 500 AA HE | Difference |
|---|---|---|---|
| Mass | 113.1 kg/m | 107 kg/m | +5.7% |
| Depth | 462.3 mm | 472 mm | -2.1% |
| Width | 279.4 mm | 300 mm | -6.9% |
| Web thickness | 10.8 mm | 10.5 mm | +2.9% |
| Flange thickness | 17.3 mm | 14 mm | +23.6% |
| Area | 143.9 cm² | 137 cm² | +5.0% |
| Second moment, major (Iy) | 55,359 cm⁴ | 54,600 cm⁴ | +1.4% |
| Plastic modulus, major (Wpl,y) | 2,671.1 cm³ | 2,580 cm³ | +3.5% |
| Elastic modulus, major (Wel,y) | 2,392.5 cm³ | 2,320 cm³ | +3.1% |
| Second moment, minor (Iz) | 6,327 cm⁴ | 6,310 cm⁴ | +0.3% |
| Plastic modulus, minor (Wpl,z) | 691.53 cm³ | 649 cm³ | +6.6% |
| Radius of gyration, minor (iz) | 6.63 cm | 6.79 cm | -2.4% |
| Torsion constant (It) | 117.8 cm⁴ | 103 cm⁴ | +14.4% |
W 18X76 to AISC Shapes Database v16.0; HE 500 AA to EN 10365 · Continental Steel. Difference is expressed relative to HE 500 AA.
How to choose between them
On stiffness, W 18X76 has the larger second moment of area: 55,359 cm⁴ against 54,600 cm⁴, a difference of 1.4%. 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, HE 500 AA is the more efficient section: 24.1 against 23.6 cm³ per kg/m, 2.1% 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. W sections are specified to AISC Shapes Database v16.0 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 5.7% weight.
In short, W 18X76 is the stronger section and HE 500 AA 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.