Steel Beam Sizes / AISC / W-Shapes / W8 / W8x40

W8x40 Steel Beam Dimensions and Properties

AISC Wide flange · v16.0

Analyze in Beam Calculator Back to W-Shapes All W8

Diagram, properties emphasis, and nearby alternatives use the selected unit system.

Units

Section diagram

W8x40 dimensions

Not to scale. Dimensions shown for reference.

Section properties

Symbols match the steel section finder. Imperial and metric values are shown side by side.

Property Imperial Metric
Weight 40.00 lb/ft 59.00 kg/m
Depth, d 8.25 in 210.00 mm
Flange width, bf 8.07 in 205.00 mm
tw 0.360 in 9.140 mm
tf 0.560 in 14.200 mm
Area 11.70 in² 7,550.00 mm²
Ix 146.00 in⁴ 60,800,000 mm⁴
Iy 49.10 in⁴ 20,400,000 mm⁴
Sx 35.50 in³ 582,000.00 mm³
Sy 12.20 in³ 200,000.00 mm³
Zx 39.80 in³ 652,000.00 mm³
Zy 18.50 in³ 303,000.00 mm³
rx 3.53 in 89.70 mm
ry 2.04 in 51.80 mm
J 1.12 in⁴ 466,000.00 mm⁴
Cw 726.00 in⁶ 195,000,000,000 mm⁶

Alternatives

Useful nearby sections

Same-series weight neighbors, closest Ix, and a nearby depth series when available — with percent change versus W8x40.

Browse W8 series →

Lighter in W8

W8x35

Weight
35.0 lb/ft (-13%)
Depth
8.12 in (-1.6%)
Ix
127.0 in⁴ (-13%)

Heavier in W8

W8x48

Weight
48.0 lb/ft (+20%)
Depth
8.50 in (+3.0%)
Ix
184.0 in⁴ (+26%)

Closest Iₓ in W8

W8x31

Weight
31.0 lb/ft (-23%)
Depth
8.00 in (-3.0%)
Ix
110.0 in⁴ (-25%)

Similar weight in W10

W10x39

Weight
39.0 lb/ft (-2.5%)
Depth
9.92 in (+20%)
Ix
209.0 in⁴ (+43%)
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Source: AISC Shapes Database v16.0 · Methodology