W 8X40 vs HE 200 B
W 8X40 is an W section from the American AISC Shapes Database; HE 200 B is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 652.21 cm³ against 642 cm³ of plastic modulus, a difference of 1.6%. W 8X40 is the lighter of the two at 59.5 kg/m against 61.3 kg/m, a saving of 2.9% on steel weight. W 8X40 is deeper, 209.6 mm against 200 mm, which matters where the floor zone is tight.
| Property | W 8X40 W | HE 200 B HE | Difference |
|---|---|---|---|
| Mass | 59.5 kg/m | 61.3 kg/m | -2.9% |
| Depth | 209.6 mm | 200 mm | +4.8% |
| Width | 205 mm | 200 mm | +2.5% |
| Web thickness | 9.1 mm | 9 mm | +1.1% |
| Flange thickness | 14.2 mm | 15 mm | -5.3% |
| Area | 75.5 cm² | 78.1 cm² | -3.3% |
| Second moment, major (Iy) | 6,077 cm⁴ | 5,700 cm⁴ | +6.6% |
| Plastic modulus, major (Wpl,y) | 652.21 cm³ | 642 cm³ | +1.6% |
| Elastic modulus, major (Wel,y) | 581.74 cm³ | 570 cm³ | +2.1% |
| Second moment, minor (Iz) | 2,044 cm⁴ | 2,000 cm⁴ | +2.2% |
| Plastic modulus, minor (Wpl,z) | 303.16 cm³ | 306 cm³ | -0.9% |
| Radius of gyration, minor (iz) | 5.18 cm | 5.07 cm | +2.2% |
| Torsion constant (It) | 46.62 cm⁴ | 59.7 cm⁴ | -21.9% |
W 8X40 to AISC Shapes Database v16.0; HE 200 B to EN 10365 · Continental Steel. Difference is expressed relative to HE 200 B.
How to choose between them
On stiffness, W 8X40 has the larger second moment of area: 6,077 cm⁴ against 5,700 cm⁴, a difference of 6.6%. 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, W 8X40 is the more efficient section: 11.0 against 10.5 cm³ per kg/m, 4.7% 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.
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 2.9% weight.
In short, W 8X40 is the stronger section and W 8X40 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.