W 16X50 vs H-400x200x9x15
W 16X50 is an W section from the American AISC Shapes Database; H-400x200x9x15 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 1507.6 cm³ against 1528 cm³ of plastic modulus, a difference of 1.3%. They weigh essentially the same, 74.4 kg/m and 75.5 kg/m. W 16X50 is deeper, 414 mm against 404 mm, which matters where the floor zone is tight.
| Property | W 16X50 W | H-400x200x9x15 MB & MC | Difference |
|---|---|---|---|
| Mass | 74.4 kg/m | 75.5 kg/m | -1.5% |
| Depth | 414 mm | 404 mm | +2.5% |
| Width | 179.6 mm | 201 mm | -10.6% |
| Web thickness | 9.7 mm | 9 mm | +7.8% |
| Flange thickness | 16 mm | 15 mm | +6.7% |
| Area | 94.8 cm² | 96.2 cm² | -1.5% |
| Second moment, major (Iy) | 27,430 cm⁴ | 27,490 cm⁴ | -0.2% |
| Plastic modulus, major (Wpl,y) | 1,507.6 cm³ | 1,528 cm³ | -1.3% |
| Elastic modulus, major (Wel,y) | 1,327.4 cm³ | 1,361 cm³ | -2.5% |
| Second moment, minor (Iz) | 1,548 cm⁴ | 2,035 cm⁴ | -23.9% |
| Plastic modulus, minor (Wpl,z) | 267.11 cm³ | 312 cm³ | -14.4% |
| Radius of gyration, minor (iz) | 4.04 cm | 4.6 cm | -12.2% |
| Torsion constant (It) | 63.27 cm⁴ | 62.3 cm⁴ | +1.6% |
W 16X50 to AISC Shapes Database v16.0; H-400x200x9x15 to Continental Steel. Difference is expressed relative to H-400x200x9x15.
How to choose between them
On stiffness, H-400x200x9x15 has the larger second moment of area: 27,490 cm⁴ against 27,430 cm⁴, a difference of 0.2%. 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, the two are equally efficient (20.3 against 20.2 cm³ per kg/m), so on a pure steel-tonnage basis there is nothing to choose between them. The decision comes down to availability, connection detailing and what the rest of the frame uses.
The two diverge much more about the minor axis: H-400x200x9x15 has 312 cm³ of minor-axis plastic modulus against 267.11 cm³, 14.4% more. If the member sees any minor-axis bending, or if it is unrestrained over a long length and lateral-torsional buckling governs, that gap decides the comparison even though the major-axis numbers looked equivalent.
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.