Steel Beam Sizes / AISC / W-Shapes / W18 / W18x40

W18x40 Steel Beam Dimensions and Properties

AISC Wide flange · v16.0

Analyze in Beam Calculator Back to W-Shapes All W18

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

Units

Section diagram

W18x40 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 60.00 kg/m
Depth, d 17.90 in 455.00 mm
Flange width, bf 6.02 in 153.00 mm
tw 0.315 in 8.000 mm
tf 0.525 in 13.300 mm
Area 11.80 in² 7,610.00 mm²
Ix 612.00 in⁴ 255,000,000 mm⁴
Iy 19.10 in⁴ 7,950,000 mm⁴
Sx 68.40 in³ 1,120,000 mm³
Sy 6.35 in³ 104,000.00 mm³
Zx 78.40 in³ 1,280,000 mm³
Zy 10.00 in³ 164,000.00 mm³
rx 7.21 in 183.00 mm
ry 1.27 in 32.30 mm
J 0.81 in⁴ 337,000.00 mm⁴
Cw 1,440.00 in⁶ 387,000,000,000 mm⁶

Alternatives

Useful nearby sections

Same-series weight neighbors, closest Ix, and a nearby depth series when available — with percent change versus W18x40.

Browse W18 series →

Lighter in W18

W18x35

Weight
35.0 lb/ft (-13%)
Depth
17.70 in (-1.1%)
Ix
510.0 in⁴ (-17%)

Heavier in W18

W18x46

Weight
46.0 lb/ft (+15%)
Depth
18.10 in (+1.1%)
Ix
712.0 in⁴ (+16%)

Closest Iₓ in W18

W18x50

Weight
50.0 lb/ft (+25%)
Depth
18.00 in (+0.6%)
Ix
800.0 in⁴ (+31%)

Similar weight in W16

W16x40

Weight
40.0 lb/ft (0.0%)
Depth
16.00 in (-11%)
Ix
518.0 in⁴ (-15%)
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Source: AISC Shapes Database v16.0 · Methodology