W16×50 vs W18×50
A side-by-side comparison of two AISC wide-flange beams, 16th Edition. Detailing dimensions to the nearest 1/16 in.
W16×50 and W18×50 both weigh 50 lb per foot, so the choice comes down to depth and stiffness rather than weight.
W18×50 is the deeper section at a nominal 18 in., versus 16 in.
W18×50 has the greater bending strength: section modulus Sx of 88.9 in³ versus 81, about 10% more.
| Property | W16×50 | W18×50 |
|---|---|---|
| Weight | 50 lb/ft | 50 lb/ft |
| Depth (d) | 16 1/4" | 18" |
| Flange width (bf) | 7 1/8" | 7 1/2" |
| Web thickness (tw) | 3/8" | 3/8" |
| Flange thickness (tf) | 5/8" | 9/16" |
| Area (A) | 14.7 in² | 14.7 in² |
| Moment of inertia (Ix) | 659 in⁴ | 800 in⁴ |
| Section modulus (Sx) | 81 in³ | 88.9 in³ |
| Plastic modulus (Zx) | 92 in³ | 101 in³ |
Open W16×50 in the interactive size chart →
Full detail: W16×50 · W18×50. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.
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