W18X311 Steel Beam — Section Properties

Dimensions

Property Value Unit
Depth (d) 22.30 in (566.4 mm)
Flange Width (bf) 12 in (304.8 mm)
Flange Thickness (tf) 2.74 in
Web Thickness (tw) 1.52 in
Area (A) 91.60 in² (591.0 cm²)
Weight 311 lb/ft (463 kg/m)

Elastic Section Properties

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 6,970 795 in⁴
Elastic Section Modulus (S) 624 132 in³
Plastic Section Modulus (Z) 754 207 in³
Radius of Gyration (r) 8.72 2.95 in

Torsional Properties

Property Value Unit
Torsional Constant (J) 176 in⁴
Warping Constant (Cw) 76,200 in⁶
Distance Between Flange Centroids (ho) 19.60 in
Effective Radius (rts) 3.53 in

Design Resources

Frequently Asked Questions

What is the weight of a W18X311 beam? 311 lb/ft (463 kg/m). A 40-ft length weighs approximately 12,440 lbs.

What is the section modulus of W18X311? Sx = 624 in³ (strong axis) and Sy = 132 in³ (weak axis). The plastic section modulus Zx = 754 in³ and Zy = 207 in³.

What steel grade is standard for W18X311? 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 W18X311? Ix = 6970 in⁴ about the strong axis and Iy = 795 in⁴ about the weak axis. The radius of gyration is rx = 8.72 in and ry = 2.95 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.