Steel Beam Sizes / AISC / S-Shapes / S8x18.4
S8x18.4 Steel Beam Dimensions and Properties
AISC American standard beams · v16.0
Diagram, properties emphasis, and nearby alternatives use the selected unit system.
Section diagram
S8x18.4 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 | 18.40 lb/ft | 27.40 kg/m |
| Depth, d | 8.00 in | 203.00 mm |
| Flange width, bf | 4.00 in | 102.00 mm |
| tw | 0.271 in | 6.880 mm |
| tf | 0.425 in | 10.800 mm |
| Area | 5.40 in² | 3,480.00 mm² |
| Ix | 57.50 in⁴ | 23,900,000 mm⁴ |
| Iy | 3.69 in⁴ | 1,540,000 mm⁴ |
| Sx | 14.40 in³ | 236,000.00 mm³ |
| Sy | 1.84 in³ | 30,200.00 mm³ |
| Zx | 16.50 in³ | 270,000.00 mm³ |
| Zy | 3.18 in³ | 52,100.00 mm³ |
| rx | 3.26 in | 82.80 mm |
| ry | 0.83 in | 21.00 mm |
| J | 0.34 in⁴ | 139,000.00 mm⁴ |
| Cw | 52.90 in⁶ | 14,200,000,000 mm⁶ |
Alternatives
Useful nearby sections
Same-series weight neighbors, closest Ix, and a nearby depth series when available — with percent change versus S8x18.4.
Source: AISC Shapes Database v16.0 · Methodology