W6×20 vs W6×25
A side-by-side comparison of two AISC wide-flange beams, 16th Edition. Detailing dimensions to the nearest 1/16 in.
W6×25 is the heavier section at 25 lb per foot, versus 20 for W6×20 (5 lb/ft more).
Both are nominally 6 in. deep.
W6×25 has the greater bending strength: section modulus Sx of 16.7 in³ versus 13.4, about 25% more.
| Property | W6×20 | W6×25 |
|---|---|---|
| Weight | 20 lb/ft | 25 lb/ft |
| Depth (d) | 6 1/4" | 6 3/8" |
| Flange width (bf) | 6" | 6 1/8" |
| Web thickness (tw) | 1/4" | 5/16" |
| Flange thickness (tf) | 3/8" | 7/16" |
| Area (A) | 5.87 in² | 7.34 in² |
| Moment of inertia (Ix) | 41.4 in⁴ | 53.4 in⁴ |
| Section modulus (Sx) | 13.4 in³ | 16.7 in³ |
| Plastic modulus (Zx) | 14.9 in³ | 18.9 in³ |
Open W6×20 in the interactive size chart →
Full detail: W6×20 · W6×25. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.
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