W 36X182 vs H-900x300x18x34-283
W 36X182 is an W section from the American AISC Shapes Database; H-900x300x18x34-283 is the closest equivalent in the European (Continental) range. H-900x300x18x34-283 carries more bending: 12340 cm³ of plastic modulus against 11765.9 cm³, 4.7% more. W 36X182 is the lighter of the two at 270.8 kg/m against 283 kg/m, a saving of 4.3% on steel weight. Both are about 917 mm deep, so either fits the same construction zone.
| Property | W 36X182 W | H-900x300x18x34-283 MB & MC | Difference |
|---|---|---|---|
| Mass | 270.8 kg/m | 283 kg/m | -4.3% |
| Depth | 922 mm | 912 mm | +1.1% |
| Width | 307.3 mm | 302 mm | +1.8% |
| Web thickness | 18.4 mm | 18 mm | +2.2% |
| Flange thickness | 30 mm | 34 mm | -11.8% |
| Area | 345.8 cm² | 360 cm² | -3.9% |
| Second moment, major (Iy) | 470,342 cm⁴ | 491,000 cm⁴ | -4.2% |
| Plastic modulus, major (Wpl,y) | 11,765.9 cm³ | 12,340 cm³ | -4.7% |
| Elastic modulus, major (Wel,y) | 10,209.1 cm³ | 10,770 cm³ | -5.2% |
| Second moment, minor (Iz) | 14,443 cm⁴ | 15,660 cm⁴ | -7.8% |
| Plastic modulus, minor (Wpl,z) | 1,486.3 cm³ | 1,622 cm³ | -8.4% |
| Radius of gyration, minor (iz) | 6.48 cm | 6.59 cm | -1.7% |
| Torsion constant (It) | 770 cm⁴ | 979 cm⁴ | -21.3% |
W 36X182 to AISC Shapes Database v16.0; H-900x300x18x34-283 to Continental Steel. Difference is expressed relative to H-900x300x18x34-283.
How to choose between them
On stiffness, H-900x300x18x34-283 has the larger second moment of area: 491,000 cm⁴ against 470,342 cm⁴, a difference of 4.2%. 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 (43.4 against 43.6 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-900x300x18x34-283 has 1622 cm³ of minor-axis plastic modulus against 1486.3 cm³, 8.4% 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 4.3% weight.
In short, H-900x300x18x34-283 is the stronger section and W 36X182 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.