W 27X217 vs HE 650 x 343
W 27X217 is an W section from the American AISC Shapes Database; HE 650 x 343 is the closest equivalent in the European (Continental) range. W 27X217 carries more bending: 11651.2 cm³ of plastic modulus against 11400 cm³, 2.2% more. W 27X217 is the lighter of the two at 322.9 kg/m against 343 kg/m, a saving of 5.9% on steel weight. W 27X217 is deeper, 721.4 mm against 680 mm, which matters where the floor zone is tight.
| Property | W 27X217 W | HE 650 x 343 HE | Difference |
|---|---|---|---|
| Mass | 322.9 kg/m | 343 kg/m | -5.9% |
| Depth | 721.4 mm | 680 mm | +6.1% |
| Width | 358.1 mm | 309 mm | +15.9% |
| Web thickness | 21.1 mm | 25 mm | -15.6% |
| Flange thickness | 38.1 mm | 46 mm | -17.2% |
| Area | 412.3 cm² | 438 cm² | -5.9% |
| Second moment, major (Iy) | 370,862 cm⁴ | 334,000 cm⁴ | +11.0% |
| Plastic modulus, major (Wpl,y) | 11,651.2 cm³ | 11,400 cm³ | +2.2% |
| Elastic modulus, major (Wel,y) | 10,274.7 cm³ | 9,820 cm³ | +4.6% |
| Second moment, minor (Iz) | 29,303 cm⁴ | 22,700 cm⁴ | +29.1% |
| Plastic modulus, minor (Wpl,z) | 2,523.6 cm³ | 2,300 cm³ | +9.7% |
| Radius of gyration, minor (iz) | 8.43 cm | 7.21 cm | +16.9% |
| Torsion constant (It) | 1,565 cm⁴ | 2,440 cm⁴ | -35.9% |
W 27X217 to AISC Shapes Database v16.0; HE 650 x 343 to EN 10365 · Continental Steel. Difference is expressed relative to HE 650 x 343.
How to choose between them
On stiffness, W 27X217 has the larger second moment of area: 370,862 cm⁴ against 334,000 cm⁴, a difference of 11.0%. 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 of steel, W 27X217 is the more efficient section: 36.1 against 33.2 cm³ per kg/m, 8.6% 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 27X217 has 2523.6 cm³ of minor-axis plastic modulus against 2300 cm³, 9.7% 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 5.9% weight.
In short, W 27X217 is the stronger section and W 27X217 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.