W 24X104 vs S 24X106
W 24X104 is an W section from the American AISC Shapes Database; S 24X106 is the closest equivalent in the American AISC Shapes Database. W 24X104 carries more bending: 4735.9 cm³ of plastic modulus against 4572 cm³, 3.6% more. They weigh essentially the same, 154.8 kg/m and 157.7 kg/m. Both are about 617 mm deep, so either fits the same construction zone.
| Property | W 24X104 W | S 24X106 S | Difference |
|---|---|---|---|
| Mass | 154.8 kg/m | 157.7 kg/m | -1.8% |
| Depth | 612.1 mm | 622.3 mm | -1.6% |
| Width | 325.1 mm | 199.9 mm | +62.6% |
| Web thickness | 12.7 mm | 15.7 mm | -19.1% |
| Flange thickness | 19 mm | 27.7 mm | -31.4% |
| Area | 198.1 cm² | 200.6 cm² | -1.2% |
| Second moment, major (Iy) | 129,032 cm⁴ | 122,372 cm⁴ | +5.4% |
| Plastic modulus, major (Wpl,y) | 4,735.9 cm³ | 4,572 cm³ | +3.6% |
| Elastic modulus, major (Wel,y) | 4,227.9 cm³ | 3,932.9 cm³ | +7.5% |
| Second moment, minor (Iz) | 10,780 cm⁴ | 3,197 cm⁴ | +237.2% |
| Plastic modulus, minor (Wpl,z) | 1,022.6 cm³ | 547.33 cm³ | +86.8% |
| Radius of gyration, minor (iz) | 7.39 cm | 3.99 cm | +85.2% |
| Torsion constant (It) | 196.5 cm⁴ | 420.4 cm⁴ | -53.3% |
W 24X104 to AISC Shapes Database v16.0; S 24X106 to AISC Shapes Database v16.0. Difference is expressed relative to S 24X106.
How to choose between them
On stiffness, W 24X104 has the larger second moment of area: 129,032 cm⁴ against 122,372 cm⁴, a difference of 5.4%. 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 24X104 is the more efficient section: 30.6 against 29.0 cm³ per kg/m, 5.5% 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 24X104 has 1022.6 cm³ of minor-axis plastic modulus against 547.33 cm³, 86.8% 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.
In short, W 24X104 is the stronger section and W 24X104 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.