W12×45 vs W16×45

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

W12×45 and W16×45 both weigh 45 lb per foot, so the choice comes down to depth and stiffness rather than weight.

W16×45 is the deeper section at a nominal 16 in., versus 12 in.

W16×45 has the greater bending strength: section modulus Sx of 72.7 in³ versus 57.7, about 26% more.

PropertyW12×45W16×45
Weight45 lb/ft45 lb/ft
Depth (d)12"16 1/8"
Flange width (bf)8"7"
Web thickness (tw)5/16"3/8"
Flange thickness (tf)9/16"9/16"
Area (A)13.1 in²13.3 in²
Moment of inertia (Ix)348 in⁴586 in⁴
Section modulus (Sx)57.7 in³72.7 in³
Plastic modulus (Zx)64.2 in³82.3 in³

Open W12×45 in the interactive size chart →

Full detail: W12×45 · W16×45. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.

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