W 33X201 vs HE 900 B
W 33X201 is an W section from the American AISC Shapes Database; HE 900 B is the closest equivalent in the European (Continental) range. They are close to interchangeable in bending: 12667.2 cm³ against 12600 cm³ of plastic modulus, a difference of 0.5%. HE 900 B is the lighter of the two at 291 kg/m against 299.1 kg/m, a saving of 2.8% on steel weight. HE 900 B is deeper, 900 mm against 856 mm, which matters where the floor zone is tight.
| Property | W 33X201 W | HE 900 B HE | Difference |
|---|---|---|---|
| Mass | 299.1 kg/m | 291 kg/m | +2.8% |
| Depth | 856 mm | 900 mm | -4.9% |
| Width | 398.8 mm | 300 mm | +32.9% |
| Web thickness | 18.2 mm | 18.5 mm | -1.6% |
| Flange thickness | 29.2 mm | 35 mm | -16.6% |
| Area | 381.3 cm² | 371 cm² | +2.8% |
| Second moment, major (Iy) | 482,828 cm⁴ | 494,000 cm⁴ | -2.3% |
| Plastic modulus, major (Wpl,y) | 12,667.2 cm³ | 12,600 cm³ | +0.5% |
| Elastic modulus, major (Wel,y) | 11,241.5 cm³ | 11,000 cm³ | +2.2% |
| Second moment, minor (Iz) | 31,176 cm⁴ | 15,800 cm⁴ | +97.3% |
| Plastic modulus, minor (Wpl,z) | 2,408.9 cm³ | 1,660 cm³ | +45.1% |
| Radius of gyration, minor (iz) | 9.04 cm | 6.53 cm | +38.4% |
| Torsion constant (It) | 865.8 cm⁴ | 1,150 cm⁴ | -24.7% |
W 33X201 to AISC Shapes Database v16.0; HE 900 B to EN 10365 · Continental Steel. Difference is expressed relative to HE 900 B.
How to choose between them
On stiffness, HE 900 B has the larger second moment of area: 494,000 cm⁴ against 482,828 cm⁴, a difference of 2.3%. 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 900 B is the more efficient section: 43.3 against 42.4 cm³ per kg/m, 2.2% 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.
The two diverge much more about the minor axis: W 33X201 has 2408.9 cm³ of minor-axis plastic modulus against 1660 cm³, 45.1% 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 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 2.8% weight.
In short, W 33X201 is the stronger section and HE 900 B 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.