AISC 360-22ASTM A992 / A6W8 Series
AISC W8x18 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 | 18 lb/ft | 26.8 kg/m |
| Cross-Sectional Area | A | 5.26 in² | 3394 mm² |
| Overall Depth | d | 8.14 in | 206.8 mm |
| Flange Width | bf | 5.25 in | 133.4 mm |
| Flange Thickness | tf | 0.33 in | 8.4 mm |
| Web Thickness | tw | 0.23 in | 5.8 mm |
| Flange Centroid Distance | ho | 7.81 in | 198.4 mm |
Bending & Buckling Properties
| Property | Symbol | Imperial (US) | Metric (SI) |
|---|---|---|---|
| Strong-Axis Inertia | Ix | 61.9 in⁴ | 25.8 ×10⁶ mm⁴ |
| Strong-Axis Elastic Modulus | Sx | 15.2 in³ | 249 ×10³ mm³ |
| Strong-Axis Plastic Modulus | Zx | 17 in³ | 279 ×10³ mm³ |
| Strong-Axis Radius of Gyration | rx | 3.43 in | 87.1 mm |
| Weak-Axis Inertia | Iy | 8 in⁴ | 3.3 ×10⁶ mm⁴ |
| Weak-Axis Elastic Modulus | Sy | 3 in³ | 50 ×10³ mm³ |
| Weak-Axis Plastic Modulus | Zy | 4.7 in³ | 76 ×10³ mm³ |
| Weak-Axis Radius of Gyration | ry | 1.23 in | 31.2 mm |
| Torsional Constant | J | 0.172 in⁴ | 72 ×10³ mm⁴ |
| Warping Constant | Cw | 192 in⁶ | 32.8 ×10⁹ mm⁶ |
| Effective Radius of Gyration | rts | 1.43 in | 36.3 mm |
AISC 360-22 Design Capacities (Fy = 50 ksi / 345 MPa)
Plastic Moment Capacity (φMp)
63.8 kip-ft
86.5 kN·m (φ = 0.90)Nominal Shear Capacity (φVn)
50.5 kips
225 kN (φ = 0.90)Flange Slenderness (λf = bf / 2tf)
7.95
✓ Compact Flange (λf ≤ 9.15)Web Slenderness (λw = h / tw)
32.5
✓ Compact Web (λw ≤ 90.5)