Steel Beam Sizes / AISC / W-Shapes / W18 / W18x55

W18x55 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

W18x55 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 55.00 lb/ft 82.00 kg/m
Depth, d 18.10 in 460.00 mm
Flange width, bf 7.53 in 191.00 mm
tw 0.390 in 9.910 mm
tf 0.630 in 16.000 mm
Area 16.20 in² 10,500.00 mm²
Ix 890.00 in⁴ 370,000,000 mm⁴
Iy 44.90 in⁴ 18,700,000 mm⁴
Sx 98.30 in³ 1,610,000 mm³
Sy 11.90 in³ 195,000.00 mm³
Zx 112.00 in³ 1,840,000 mm³
Zy 18.50 in³ 303,000.00 mm³
rx 7.41 in 188.00 mm
ry 1.67 in 42.40 mm
J 1.66 in⁴ 691,000.00 mm⁴
Cw 3,430.00 in⁶ 921,000,000,000 mm⁶

Alternatives

Useful nearby sections

Same-series weight neighbors, closest Ix, and a nearby depth series when available — with percent change versus W18x55.

Browse W18 series →

Lighter in W18

W18x50

Weight
50.0 lb/ft (-9.1%)
Depth
18.00 in (-0.6%)
Ix
800.0 in⁴ (-10%)

Heavier in W18

W18x60

Weight
60.0 lb/ft (+9.1%)
Depth
18.20 in (+0.6%)
Ix
984.0 in⁴ (+11%)

Closest Iₓ in W18

W18x46

Weight
46.0 lb/ft (-16%)
Depth
18.10 in (0.0%)
Ix
712.0 in⁴ (-20%)

Similar weight in W21

W21x55

Weight
55.0 lb/ft (0.0%)
Depth
20.80 in (+15%)
Ix
1,140.0 in⁴ (+28%)
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Source: AISC Shapes Database v16.0 · Methodology