AISC 360-22ASTM A992 / A6W18 Series
AISC W18x55 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 | 55 lb/ft | 81.8 kg/m |
| Cross-Sectional Area | A | 16.2 in² | 10452 mm² |
| Overall Depth | d | 18.1 in | 459.7 mm |
| Flange Width | bf | 7.53 in | 191.3 mm |
| Flange Thickness | tf | 0.63 in | 16 mm |
| Web Thickness | tw | 0.39 in | 9.9 mm |
| Flange Centroid Distance | ho | 17.5 in | 444.5 mm |
Bending & Buckling Properties
| Property | Symbol | Imperial (US) | Metric (SI) |
|---|---|---|---|
| Strong-Axis Inertia | Ix | 890 in⁴ | 370.4 ×10⁶ mm⁴ |
| Strong-Axis Elastic Modulus | Sx | 98.3 in³ | 1611 ×10³ mm³ |
| Strong-Axis Plastic Modulus | Zx | 112 in³ | 1835 ×10³ mm³ |
| Strong-Axis Radius of Gyration | rx | 7.41 in | 188.2 mm |
| Weak-Axis Inertia | Iy | 44.9 in⁴ | 18.7 ×10⁶ mm⁴ |
| Weak-Axis Elastic Modulus | Sy | 11.9 in³ | 195 ×10³ mm³ |
| Weak-Axis Plastic Modulus | Zy | 18.5 in³ | 303 ×10³ mm³ |
| Weak-Axis Radius of Gyration | ry | 1.67 in | 42.4 mm |
| Torsional Constant | J | 1.66 in⁴ | 691 ×10³ mm⁴ |
| Warping Constant | Cw | 5398.6 in⁶ | 921.1 ×10⁹ mm⁶ |
| Effective Radius of Gyration | rts | 2 in | 50.8 mm |
AISC 360-22 Design Capacities (Fy = 50 ksi / 345 MPa)
Plastic Moment Capacity (φMp)
420 kip-ft
569.9 kN·m (φ = 0.90)Nominal Shear Capacity (φVn)
190.6 kips
848.4 kN (φ = 0.90)Flange Slenderness (λf = bf / 2tf)
5.98
✓ Compact Flange (λf ≤ 9.15)Web Slenderness (λw = h / tw)
43.2
✓ Compact Web (λw ≤ 90.5)