W14×68 vs W21×68
A side-by-side comparison of two AISC wide-flange beams, 16th Edition. Detailing dimensions to the nearest 1/16 in.
W14×68 and W21×68 both weigh 68 lb per foot, so the choice comes down to depth and stiffness rather than weight.
W21×68 is the deeper section at a nominal 21 in., versus 14 in.
W21×68 has the greater bending strength: section modulus Sx of 140 in³ versus 103, about 36% more.
| Property | W14×68 | W21×68 |
|---|---|---|
| Weight | 68 lb/ft | 68 lb/ft |
| Depth (d) | 14" | 21 1/8" |
| Flange width (bf) | 10" | 8 1/4" |
| Web thickness (tw) | 7/16" | 7/16" |
| Flange thickness (tf) | 3/4" | 11/16" |
| Area (A) | 20 in² | 20 in² |
| Moment of inertia (Ix) | 722 in⁴ | 1480 in⁴ |
| Section modulus (Sx) | 103 in³ | 140 in³ |
| Plastic modulus (Zx) | 115 in³ | 160 in³ |
Open W14×68 in the interactive size chart →
Full detail: W14×68 · W21×68. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.
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