AISC 360-22ASTM A992 / A6W18 Series
AISC W18x40 Properties & Dimensions
Standard wide flange I-beam cross-section properties, geometric dimensions, and LRFD design capacities per AISC Steel Construction Manual 15th/16th Edition.
Cross-Section Technical Schematic
Dual Units: Imperial (US) · SI MetricGeometric Dimensions & Area
| Property | Symbol | Imperial (US) | Metric (SI) |
|---|---|---|---|
| Nominal Weight | w | 40 lb/ft | 59.5 kg/m |
| Cross-Sectional Area | A | 11.8 in² | 7613 mm² |
| Overall Depth | d | 17.9 in | 454.7 mm |
| Flange Width | bf | 6.02 in | 152.9 mm |
| Flange Thickness | tf | 0.525 in | 13.3 mm |
| Web Thickness | tw | 0.315 in | 8 mm |
| Flange Centroid Distance | ho | 17.4 in | 442 mm |
Bending & Buckling Properties
| Property | Symbol | Imperial (US) | Metric (SI) |
|---|---|---|---|
| Strong-Axis Inertia | Ix | 612 in⁴ | 254.7 ×10⁶ mm⁴ |
| Strong-Axis Elastic Modulus | Sx | 68.4 in³ | 1121 ×10³ mm³ |
| Strong-Axis Plastic Modulus | Zx | 78.4 in³ | 1285 ×10³ mm³ |
| Strong-Axis Radius of Gyration | rx | 7.21 in | 183.1 mm |
| Weak-Axis Inertia | Iy | 19.1 in⁴ | 8 ×10⁶ mm⁴ |
| Weak-Axis Elastic Modulus | Sy | 6.4 in³ | 104 ×10³ mm³ |
| Weak-Axis Plastic Modulus | Zy | 10 in³ | 164 ×10³ mm³ |
| Weak-Axis Radius of Gyration | ry | 1.27 in | 32.3 mm |
| Torsional Constant | J | 0.81 in⁴ | 337 ×10³ mm⁴ |
| Warping Constant | Cw | 2266.5 in⁶ | 386.7 ×10⁹ mm⁶ |
| Effective Radius of Gyration | rts | 1.56 in | 39.6 mm |
AISC 360-22 Design Capacities (Fy = 50 ksi / 345 MPa)
Plastic Moment Capacity (φMp)
294 kip-ft
398.9 kN·m (φ = 0.90)Nominal Shear Capacity (φVn)
152.2 kips
677.7 kN (φ = 0.90)Flange Slenderness (λf = bf / 2tf)
5.73
✓ Compact Flange (λf ≤ 9.15)Web Slenderness (λw = h / tw)
53.5
✓ Compact Web (λw ≤ 90.5)