W30×99 vs W30×108
A side-by-side comparison of two AISC wide-flange beams, 16th Edition. Detailing dimensions to the nearest 1/16 in.
W30×108 is the heavier section at 108 lb per foot, versus 99 for W30×99 (9 lb/ft more).
Both are nominally 30 in. deep.
W30×108 has the greater bending strength: section modulus Sx of 299 in³ versus 269, about 11% more.
| Property | W30×99 | W30×108 |
|---|---|---|
| Weight | 99 lb/ft | 108 lb/ft |
| Depth (d) | 29 5/8" | 29 7/8" |
| Flange width (bf) | 10 1/2" | 10 1/2" |
| Web thickness (tw) | 1/2" | 9/16" |
| Flange thickness (tf) | 11/16" | 3/4" |
| Area (A) | 29 in² | 31.7 in² |
| Moment of inertia (Ix) | 3990 in⁴ | 4470 in⁴ |
| Section modulus (Sx) | 269 in³ | 299 in³ |
| Plastic modulus (Zx) | 312 in³ | 346 in³ |
Open W30×99 in the interactive size chart →
Full detail: W30×99 · W30×108. Verify critical dimensions against the current AISC Steel Construction Manual before fabrication.
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