S18X70 Steel S-shape — Section Properties
Dimensions
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 18 | 457.2 mm |
| Flange Width (bf) | 6.25 | 15.88 cm |
| Flange Thickness (tf) | 0.691 | 17.6 mm |
| Web Thickness (tw) | 0.711 | 18.1 mm |
| Area (A) | 20.5 in² | 132.3 cm² |
| Weight | 70 lb/ft | 104.2 kg/m |
Elastic Section Properties
| Property | Strong Axis (X-X) | Weak Axis (Y-Y) | Unit |
|---|---|---|---|
| Moment of Inertia (I) | 923 | 24 | in⁴ |
| Elastic Section Modulus (S) | 103 | 7.69 | in³ |
| Plastic Section Modulus (Z) | 124 | 14.3 | in³ |
| Radius of Gyration (r) | 6.7 | 1.08 | in |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 4.1 | in⁴ |
| Warping Constant (Cw) | 1800 | in⁶ |
| Distance Between Flange Centroids (ho) | 17.3 | in |
| Effective Radius (rts) | 1.42 | in |
Design Resources
- Beam Capacity Calculator — Check S18X70 for your span and loads
- Column Capacity Calculator — Check S18X70 as a column
- Section Properties Database — Compare with other sections
- Steel Beam Sizes Reference — Full dimension table
- Steel Grades Reference — Material properties
Frequently Asked Questions
What is the weight of a S18X70 beam? 70 lb/ft (104.2 kg/m).
What is the section modulus of S18X70? Sx = 103 in³, Zx = 124 in³ (strong axis). Sy = 7.69 in³, Zy = 14.3 in³ (weak axis).
What steel grade is standard for S18X70? ASTM A36 (Fy = 36 ksi) for S-shapes. Verify with mill certificate.
What is the moment of inertia of S18X70? Ix = 923 in⁴ about the strong axis and Iy = 24 in⁴ about the weak axis. The radius of gyration is rx = 6.7 in and ry = 1.08 in.
Related Pages
Educational reference only. Verify all section properties against the current AISC Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.