Steel Beam Sizes / AISC / ST Tees / ST12x40

ST12x40 Steel Beam Dimensions and Properties

AISC American standard tees · v16.0

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

Units

Section diagram

ST12x40 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 59.50 kg/m
Depth, d 12.00 in 305.00 mm
Flange width, bf 7.00 in 178.00 mm
tw 0.500 in 12.700 mm
tf 0.870 in 22.100 mm
Area 11.70 in² 7,550.00 mm²
Ix 162.00 in⁴ 67,400,000 mm⁴
Iy 21.00 in⁴ 8,740,000 mm⁴
Sx 18.60 in³ 305,000.00 mm³
Sy 6.00 in³ 98,300.00 mm³
Zx 33.60 in³ 551,000.00 mm³
Zy 10.40 in³ 170,000.00 mm³
rx 3.72 in 94.50 mm
ry 1.34 in 34.00 mm
J 2.44 in⁴ 1,020,000 mm⁴
Cw 6.94 in⁶ 1,860,000,000 mm⁶

Alternatives

Useful nearby sections

Same-series weight neighbors, closest Ix, and a nearby depth series when available — with percent change versus ST12x40.

Heavier in ST12

ST12x45

Weight
45.0 lb/ft (+13%)
Depth
12.00 in (0.0%)
Ix
190.0 in⁴ (+17%)

Closest Iₓ in ST12

ST12x50

Weight
50.0 lb/ft (+25%)
Depth
12.00 in (0.0%)
Ix
215.0 in⁴ (+33%)

Similar weight in ST10

ST10x37.5

Weight
37.5 lb/ft (-6.3%)
Depth
10.00 in (-17%)
Ix
109.0 in⁴ (-33%)
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Source: AISC Shapes Database v16.0 · Methodology