W21X166 Steel Beam — Section Properties
Dimensions
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 22.50 | in (571.5 mm) |
| Flange Width (bf) | 12.40 | in (315.0 mm) |
| Flange Thickness (tf) | 1.36 | in |
| Web Thickness (tw) | 0.75 | in |
| Area (A) | 48.80 | in² (314.9 cm²) |
| Weight | 166 | lb/ft (247 kg/m) |
Elastic Section Properties
| Property | Strong Axis (X-X) | Weak Axis (Y-Y) | Unit |
|---|---|---|---|
| Moment of Inertia (I) | 4,280 | 435 | in⁴ |
| Elastic Section Modulus (S) | 380 | 70 | in³ |
| Plastic Section Modulus (Z) | 432 | 108 | in³ |
| Radius of Gyration (r) | 9.36 | 2.99 | in |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 23.60 | in⁴ |
| Warping Constant (Cw) | 48,500 | in⁶ |
| Distance Between Flange Centroids (ho) | 21.10 | in |
| Effective Radius (rts) | 3.48 | in |
Design Resources
- Beam Capacity Calculator — Check W21X166 for your span and loads
- Column Capacity Calculator — Check W21X166 as a column
- Section Properties Database — Compare with other sections
- Steel Beam Sizes Reference — Full W-shape dimension table
- Steel Grades Reference — A992/A572 material properties
Frequently Asked Questions
What is the weight of a W21X166 beam? 166 lb/ft (247 kg/m). A 40-ft length weighs approximately 6,640 lbs.
What is the section modulus of W21X166? Sx = 380 in³ (strong axis) and Sy = 70 in³ (weak axis). The plastic section modulus Zx = 432 in³ and Zy = 108 in³.
What steel grade is standard for W21X166? Typically ASTM A992 (Fy = 50 ksi, Fu = 65 ksi) for W-shapes. Also available in A572 Grade 50 or A36. Verify with mill certificate.
What is the moment of inertia of W21X166? Ix = 4280 in⁴ about the strong axis and Iy = 435 in⁴ about the weak axis. The radius of gyration is rx = 9.36 in and ry = 2.99 in.
Related Pages
- Steel Beam Sizes Reference
- Beam Capacity Calculator
- Column Capacity Calculator
- Section Properties Database
Educational reference only. Verify all section properties against the current AISC Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.