W 30X99 vs IPE 750 x 147
W 30X99 is an W section from the American AISC Shapes Database; IPE 750 x 147 is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 5112.8 cm³ against 5110 cm³ of plastic modulus, a difference of 0.1%. They weigh essentially the same, 147.3 kg/m and 147 kg/m. Both are about 754 mm deep, so either fits the same construction zone.
| Property | W 30X99 W | IPE 750 x 147 IPE | Difference |
|---|---|---|---|
| Mass | 147.3 kg/m | 147 kg/m | +0.2% |
| Depth | 754.4 mm | 753 mm | +0.2% |
| Width | 266.7 mm | 265 mm | +0.6% |
| Web thickness | 13.2 mm | 13.2 mm | same |
| Flange thickness | 17 mm | 17 mm | same |
| Area | 187.1 cm² | 188 cm² | -0.5% |
| Second moment, major (Iy) | 166,076 cm⁴ | 166,000 cm⁴ | same |
| Plastic modulus, major (Wpl,y) | 5,112.8 cm³ | 5,110 cm³ | +0.1% |
| Elastic modulus, major (Wel,y) | 4,408.1 cm³ | 4,410 cm³ | same |
| Second moment, minor (Iz) | 5,328 cm⁴ | 5,290 cm⁴ | +0.7% |
| Plastic modulus, minor (Wpl,z) | 632.54 cm³ | 631 cm³ | +0.2% |
| Radius of gyration, minor (iz) | 5.33 cm | 5.31 cm | +0.4% |
| Torsion constant (It) | 156.9 cm⁴ | 157 cm⁴ | -0.1% |
W 30X99 to AISC Shapes Database v16.0; IPE 750 x 147 to EN 10365 · Continental Steel. Difference is expressed relative to IPE 750 x 147.
How to choose between them
On stiffness, W 30X99 has the larger second moment of area: 166,076 cm⁴ against 166,000 cm⁴, a difference of 0.0%. 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, the two are equally efficient (34.7 against 34.8 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.
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 IPE 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 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.