W18×40 vs W18×46
A side-by-side comparison of two AISC wide-flange beams, 16th Edition. Detailing dimensions to the nearest 1/16 in.
W18×46 is the heavier section at 46 lb per foot, versus 40 for W18×40 (6 lb/ft more).
Both are nominally 18 in. deep.
W18×46 has the greater bending strength: section modulus Sx of 78.8 in³ versus 68.4, about 15% more.
| Property | W18×40 | W18×46 |
|---|---|---|
| Weight | 40 lb/ft | 46 lb/ft |
| Depth (d) | 17 7/8" | 18" |
| Flange width (bf) | 6" | 6" |
| Web thickness (tw) | 5/16" | 3/8" |
| Flange thickness (tf) | 1/2" | 5/8" |
| Area (A) | 11.8 in² | 13.5 in² |
| Moment of inertia (Ix) | 612 in⁴ | 712 in⁴ |
| Section modulus (Sx) | 68.4 in³ | 78.8 in³ |
| Plastic modulus (Zx) | 78.4 in³ | 90.7 in³ |
Open W18×40 in the interactive size chart →
Full detail: W18×40 · W18×46. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.
Browse more: size comparisons · Steel Beam Size Chart