S8X18.4 Steel S-shape — Section Properties
Dimensions
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 8 | 203.2 mm |
| Flange Width (bf) | 4 | 10.16 cm |
| Flange Thickness (tf) | 0.425 | 10.8 mm |
| Web Thickness (tw) | 0.271 | 6.9 mm |
| Area (A) | 5.4 in² | 34.8 cm² |
| Weight | 18.4 lb/ft | 27.4 kg/m |
Elastic Section Properties
| Property | Strong Axis (X-X) | Weak Axis (Y-Y) | Unit |
|---|---|---|---|
| Moment of Inertia (I) | 57.5 | 3.69 | in⁴ |
| Elastic Section Modulus (S) | 14.4 | 1.84 | in³ |
| Plastic Section Modulus (Z) | 16.5 | 3.18 | in³ |
| Radius of Gyration (r) | 3.26 | 0.827 | in |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 0.335 | in⁴ |
| Warping Constant (Cw) | 52.9 | in⁶ |
| Distance Between Flange Centroids (ho) | 7.58 | in |
| Effective Radius (rts) | 0.985 | in |
Design Resources
- Beam Capacity Calculator — Check S8X18.4 for your span and loads
- Column Capacity Calculator — Check S8X18.4 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 S8X18.4 beam? 18.4 lb/ft (27.4 kg/m).
What is the section modulus of S8X18.4? Sx = 14.4 in³, Zx = 16.5 in³ (strong axis). Sy = 1.84 in³, Zy = 3.18 in³ (weak axis).
What steel grade is standard for S8X18.4? ASTM A36 (Fy = 36 ksi) for S-shapes. Verify with mill certificate.
What is the moment of inertia of S8X18.4? Ix = 57.5 in⁴ about the strong axis and Iy = 3.69 in⁴ about the weak axis. The radius of gyration is rx = 3.26 in and ry = 0.827 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.