W40×431 vs W40×503

A side-by-side comparison of two AISC wide-flange beams, 16th Edition. Detailing dimensions to the nearest 1/16 in.

W40×503 is the heavier section at 503 lb per foot, versus 431 for W40×431 (72 lb/ft more).

Both are nominally 40 in. deep.

W40×503 has the greater bending strength: section modulus Sx of 1980 in³ versus 1690, about 17% more.

PropertyW40×431W40×503
Weight431 lb/ft503 lb/ft
Depth (d)41 1/4"42"
Flange width (bf)16 1/4"16 3/8"
Web thickness (tw)1 5/16"1 9/16"
Flange thickness (tf)2 3/8"2 3/4"
Area (A)127 in²148 in²
Moment of inertia (Ix)34800 in⁴41600 in⁴
Section modulus (Sx)1690 in³1980 in³
Plastic modulus (Zx)1960 in³2320 in³

Open W40×431 in the interactive size chart →

Full detail: W40×431 · W40×503. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.

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