W40×397 vs W40×431
A side-by-side comparison of two AISC wide-flange beams, 16th Edition. Detailing dimensions to the nearest 1/16 in.
W40×431 is the heavier section at 431 lb per foot, versus 397 for W40×397 (34 lb/ft more).
Both are nominally 40 in. deep.
W40×431 has the greater bending strength: section modulus Sx of 1690 in³ versus 1560, about 8% more.
| Property | W40×397 | W40×431 |
|---|---|---|
| Weight | 397 lb/ft | 431 lb/ft |
| Depth (d) | 41" | 41 1/4" |
| Flange width (bf) | 16 1/8" | 16 1/4" |
| Web thickness (tw) | 1 1/4" | 1 5/16" |
| Flange thickness (tf) | 2 3/16" | 2 3/8" |
| Area (A) | 117 in² | 127 in² |
| Moment of inertia (Ix) | 32000 in⁴ | 34800 in⁴ |
| Section modulus (Sx) | 1560 in³ | 1690 in³ |
| Plastic modulus (Zx) | 1800 in³ | 1960 in³ |
Open W40×397 in the interactive size chart →
Full detail: W40×397 · W40×431. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.
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