W 14X176 vs UC 305×305×283
W 14X176 is an W section from the American AISC Shapes Database; UC 305×305×283 is the closest equivalent in the UK Blue Book (SCI P363). W 14X176 carries more bending: 5243.9 cm³ of plastic modulus against 5110 cm³, 2.6% more. W 14X176 is the lighter of the two at 261.9 kg/m against 282.9 kg/m, a saving of 7.4% on steel weight. W 14X176 is deeper, 386.1 mm against 365.3 mm, which matters where the floor zone is tight.
| Property | W 14X176 W | UC 305×305×283 UC | Difference |
|---|---|---|---|
| Mass | 261.9 kg/m | 282.9 kg/m | -7.4% |
| Depth | 386.1 mm | 365.3 mm | +5.7% |
| Width | 398.8 mm | 322.2 mm | +23.8% |
| Web thickness | 21.1 mm | 26.8 mm | -21.3% |
| Flange thickness | 33.3 mm | 44.1 mm | -24.5% |
| Area | 334.2 cm² | 360 cm² | -7.2% |
| Second moment, major (Iy) | 89,074 cm⁴ | 78,900 cm⁴ | +12.9% |
| Plastic modulus, major (Wpl,y) | 5,243.9 cm³ | 5,110 cm³ | +2.6% |
| Elastic modulus, major (Wel,y) | 4,604.8 cm³ | 4,320 cm³ | +6.6% |
| Second moment, minor (Iz) | 34,880 cm⁴ | 24,600 cm⁴ | +41.8% |
| Plastic modulus, minor (Wpl,z) | 2,671.1 cm³ | 2,340 cm³ | +14.1% |
| Radius of gyration, minor (iz) | 10.21 cm | 8.27 cm | +23.5% |
| Torsion constant (It) | 1,103 cm⁴ | 2,030 cm⁴ | -45.7% |
W 14X176 to AISC Shapes Database v16.0; UC 305×305×283 to BS EN 10365:2017. Difference is expressed relative to UC 305×305×283.
How to choose between them
On stiffness, W 14X176 has the larger second moment of area: 89,074 cm⁴ against 78,900 cm⁴, a difference of 12.9%. 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 14X176 is the more efficient section: 20.0 against 18.1 cm³ per kg/m, 10.8% 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 14X176 has 2671.1 cm³ of minor-axis plastic modulus against 2340 cm³, 14.1% 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 UC to BS EN 10365:2017; 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 7.4% weight.
In short, W 14X176 is the stronger section and W 14X176 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.