W30X391 Steel Beam — Section Properties
Dimensions
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 33.20 | in (843.3 mm) |
| Flange Width (bf) | 15.60 | in (396.2 mm) |
| Flange Thickness (tf) | 2.44 | in |
| Web Thickness (tw) | 1.36 | in |
| Area (A) | 115 | in² (742.0 cm²) |
| Weight | 391 | lb/ft (582 kg/m) |
Elastic Section Properties
| Property | Strong Axis (X-X) | Weak Axis (Y-Y) | Unit |
|---|---|---|---|
| Moment of Inertia (I) | 20,700 | 1,550 | in⁴ |
| Elastic Section Modulus (S) | 1,250 | 198 | in³ |
| Plastic Section Modulus (Z) | 1,450 | 310 | in³ |
| Radius of Gyration (r) | 13.40 | 3.67 | in |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 173 | in⁴ |
| Warping Constant (Cw) | 366,000 | in⁶ |
| Distance Between Flange Centroids (ho) | 30.80 | in |
| Effective Radius (rts) | 4.37 | in |
Design Resources
- Beam Capacity Calculator — Check W30X391 for your span and loads
- Column Capacity Calculator — Check W30X391 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 W30X391 beam? 391 lb/ft (582 kg/m). A 40-ft length weighs approximately 15,640 lbs.
What is the section modulus of W30X391? Sx = 1250 in³ (strong axis) and Sy = 198 in³ (weak axis). The plastic section modulus Zx = 1450 in³ and Zy = 310 in³.
What steel grade is standard for W30X391? 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 W30X391? Ix = 20700 in⁴ about the strong axis and Iy = 1550 in⁴ about the weak axis. The radius of gyration is rx = 13.40 in and ry = 3.67 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.