AISC 360-22ASTM A992 / A6W8 Series
AISC W8x31 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 | 31 lb/ft | 46.1 kg/m |
| Cross-Sectional Area | A | 9.13 in² | 5890 mm² |
| Overall Depth | d | 8 in | 203.2 mm |
| Flange Width | bf | 8 in | 203.2 mm |
| Flange Thickness | tf | 0.435 in | 11 mm |
| Web Thickness | tw | 0.285 in | 7.2 mm |
| Flange Centroid Distance | ho | 7.57 in | 192.3 mm |
Bending & Buckling Properties
| Property | Symbol | Imperial (US) | Metric (SI) |
|---|---|---|---|
| Strong-Axis Inertia | Ix | 110 in⁴ | 45.8 ×10⁶ mm⁴ |
| Strong-Axis Elastic Modulus | Sx | 27.5 in³ | 451 ×10³ mm³ |
| Strong-Axis Plastic Modulus | Zx | 30.4 in³ | 498 ×10³ mm³ |
| Strong-Axis Radius of Gyration | rx | 3.47 in | 88.1 mm |
| Weak-Axis Inertia | Iy | 37.1 in⁴ | 15.4 ×10⁶ mm⁴ |
| Weak-Axis Elastic Modulus | Sy | 9.3 in³ | 152 ×10³ mm³ |
| Weak-Axis Plastic Modulus | Zy | 14.1 in³ | 231 ×10³ mm³ |
| Weak-Axis Radius of Gyration | ry | 2.02 in | 51.3 mm |
| Torsional Constant | J | 0.536 in⁴ | 223 ×10³ mm⁴ |
| Warping Constant | Cw | 834.2 in⁶ | 142.3 ×10⁹ mm⁶ |
| Effective Radius of Gyration | rts | 2.26 in | 57.4 mm |
AISC 360-22 Design Capacities (Fy = 50 ksi / 345 MPa)
Plastic Moment Capacity (φMp)
114 kip-ft
154.7 kN·m (φ = 0.90)Nominal Shear Capacity (φVn)
61.6 kips
274 kN (φ = 0.90)Flange Slenderness (λf = bf / 2tf)
9.2
Non-compact FlangeWeb Slenderness (λw = h / tw)
25
✓ Compact Web (λw ≤ 90.5)