W 12X72 vs HP 12X74
W 12X72 is an W section from the American AISC Shapes Database; HP 12X74 is the closest equivalent in the American AISC Shapes Database. W 12X72 carries more bending: 1769.8 cm³ of plastic modulus against 1720.6 cm³, 2.9% more. W 12X72 is the lighter of the two at 107.1 kg/m against 110.1 kg/m, a saving of 2.7% on steel weight. Both are about 310 mm deep, so either fits the same construction zone.
| Property | W 12X72 W | HP 12X74 HP | Difference |
|---|---|---|---|
| Mass | 107.1 kg/m | 110.1 kg/m | -2.7% |
| Depth | 312.4 mm | 307.3 mm | +1.7% |
| Width | 304.8 mm | 309.9 mm | -1.6% |
| Web thickness | 10.9 mm | 15.4 mm | -29.2% |
| Flange thickness | 17 mm | 15.5 mm | +9.7% |
| Area | 136.1 cm² | 140.6 cm² | -3.2% |
| Second moment, major (Iy) | 24,849 cm⁴ | 23,684 cm⁴ | +4.9% |
| Plastic modulus, major (Wpl,y) | 1,769.8 cm³ | 1,720.6 cm³ | +2.9% |
| Elastic modulus, major (Wel,y) | 1,596.1 cm³ | 1,537.1 cm³ | +3.8% |
| Second moment, minor (Iz) | 8,117 cm⁴ | 7,742 cm⁴ | +4.8% |
| Plastic modulus, minor (Wpl,z) | 806.24 cm³ | 763.64 cm³ | +5.6% |
| Radius of gyration, minor (iz) | 7.72 cm | 7.42 cm | +4.0% |
| Torsion constant (It) | 122 cm⁴ | 124 cm⁴ | -1.6% |
W 12X72 to AISC Shapes Database v16.0; HP 12X74 to AISC Shapes Database v16.0. Difference is expressed relative to HP 12X74.
How to choose between them
On stiffness, W 12X72 has the larger second moment of area: 24,849 cm⁴ against 23,684 cm⁴, a difference of 4.9%. 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 12X72 is the more efficient section: 16.5 against 15.6 cm³ per kg/m, 5.7% 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.
In short, W 12X72 is the stronger section and W 12X72 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.