Steel Beam Sizes / AISC / S-Shapes / S18x70

S18x70 Steel Beam Dimensions and Properties

AISC American standard beams · v16.0

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

Units

Section diagram

S18x70 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 70.00 lb/ft 104.00 kg/m
Depth, d 18.00 in 457.00 mm
Flange width, bf 6.25 in 159.00 mm
tw 0.711 in 18.100 mm
tf 0.691 in 17.600 mm
Area 20.50 in² 13,200.00 mm²
Ix 923.00 in⁴ 384,000,000 mm⁴
Iy 24.00 in⁴ 9,990,000 mm⁴
Sx 103.00 in³ 1,690,000 mm³
Sy 7.69 in³ 126,000.00 mm³
Zx 124.00 in³ 2,030,000 mm³
Zy 14.30 in³ 234,000.00 mm³
rx 6.70 in 170.00 mm
ry 1.08 in 27.40 mm
J 4.10 in⁴ 1,710,000 mm⁴
Cw 1,800.00 in⁶ 483,000,000,000 mm⁶

Alternatives

Useful nearby sections

Same-series weight neighbors, closest Ix, and a nearby depth series when available — with percent change versus S18x70.

Lighter in S18

S18x54.7

Weight
54.7 lb/ft (-22%)
Depth
18.00 in (0.0%)
Ix
801.0 in⁴ (-13%)

Similar weight in S20

S20x66

Weight
66.0 lb/ft (-5.7%)
Depth
20.00 in (+11%)
Ix
1,190.0 in⁴ (+29%)
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Source: AISC Shapes Database v16.0 · Methodology