W18X158 Steel Beam — Section Properties

Dimensions

Property Value Unit
Depth (d) 19.70 in (500.4 mm)
Flange Width (bf) 11.30 in (287.0 mm)
Flange Thickness (tf) 1.44 in
Web Thickness (tw) 0.81 in
Area (A) 46.30 in² (298.7 cm²)
Weight 158 lb/ft (235 kg/m)

Elastic Section Properties

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 3,060 347 in⁴
Elastic Section Modulus (S) 310 61.40 in³
Plastic Section Modulus (Z) 356 94.80 in³
Radius of Gyration (r) 8.12 2.74 in

Torsional Properties

Property Value Unit
Torsional Constant (J) 25.20 in⁴
Warping Constant (Cw) 29,000 in⁶
Distance Between Flange Centroids (ho) 18.30 in
Effective Radius (rts) 3.20 in

Design Resources

Frequently Asked Questions

What is the weight of a W18X158 beam? 158 lb/ft (235 kg/m). A 40-ft length weighs approximately 6,320 lbs.

What is the section modulus of W18X158? Sx = 310 in³ (strong axis) and Sy = 61.4 in³ (weak axis). The plastic section modulus Zx = 356 in³ and Zy = 94.8 in³.

What steel grade is standard for W18X158? 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 W18X158? Ix = 3060 in⁴ about the strong axis and Iy = 347 in⁴ about the weak axis. The radius of gyration is rx = 8.12 in and ry = 2.74 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.