W40×278 wide-flange beam
Detailing dimensions and section properties from the AISC Shapes Database, 16th Edition. Values are shown to the nearest 1/16 in. as they appear on a shop drawing.
W40×278 measures 40 1/8 in. deep with a 12 in. flange, on a 1 in. web and 1 13/16 in. flanges.
At 278 lb per foot it is one of the 24 W40 sizes, which run from 149 to 655 lb/ft.
For strong-axis bending its section modulus is Sx = 1020 in³ and its moment of inertia Ix = 20500 in⁴, with a plastic modulus Zx = 1190 in³.
Detailing dimensions
| Depth (d) | 40 1/8" |
|---|---|
| Flange width (bf) | 12" |
| Web thickness (tw) | 1" |
| Flange thickness (tf) | 1 13/16" |
| k (detailing) | 3 1/16" |
| Workable gage (g) | 7 1/2" |
Section properties
| Weight | 278 lb/ft |
|---|---|
| Area (A) | 82.3 in² |
| Ix | 20500 in⁴ |
| Sx | 1020 in³ |
| Zx | 1190 in³ |
| rx | 15.8 in |
| Iy | 521 in⁴ |
| Sy | 87.1 in³ |
| Zy | 140 in³ |
| ry | 2.52 in |
| J | 65 in⁴ |
Other W40 sizes
Same nominal size, different weight — useful when you are checking a substitution or a lighter section.
All W40 sizes and dimensions →
Similar weight wide-flange beams
Comparable 278 lb/ft sections in other wide-flange beam sizes.
Compare W40×278 with a nearby size
Detailing values are rounded to the nearest 1/16 in. per the AISC Steel Construction Manual. Verify critical dimensions against the current Manual before fabrication. Need W40×278 cut, formed, or fabricated? Huntington Steel & Supply Co.
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