Section Properties
W8x31 Section Properties
American wide-flange (W) profile — dimensions, area, moments of inertia, section moduli, and torsional properties, ready to use in an AISC design.
Dimensions
| Property | Value |
|---|---|
| Depth, h | 203.2 mm |
| Width, b | 203.2 mm |
| Web thickness, tw | 7.24 mm |
| Flange thickness, tf | 11.05 mm |
| Root radius, r | 10.0 mm |
Section Properties
| Property | Value |
|---|---|
| Area, A | 5,890 mm² |
| Mass (computed, ρ = 7850 kg/m³) | 46.2 kg/m |
| Second moment of area, Iy (major axis) | 45.80 × 10⁶ mm⁴ |
| Second moment of area, Iz (minor axis) | 15.440 × 10⁶ mm⁴ |
| Elastic section modulus, Wely | 451.0 × 10³ mm³ |
| Plastic section modulus, Wply | 498.0 × 10³ mm³ |
| Elastic section modulus, Welz | 151.90 × 10³ mm³ |
| Plastic section modulus, Wplz | 231.10 × 10³ mm³ |
| Radius of gyration, iy | 88.1 mm |
| Radius of gyration, iz | 51.3 mm |
| Torsion constant, It | 22.31 × 10⁴ mm⁴ |
| Warping constant, Iw | 0.14230 × 10¹² mm⁶ |
AISC Lateral-Torsional Buckling Terms
| Property | Value |
|---|---|
| Effective radius of gyration for LTB, rts | 57.4 mm |
| Distance between flange centroids, ho | 192.3 mm |
| Flange slenderness, bf/2tf | 9.19 |
| Web slenderness, h/tw | 22.3 |
| AISC nominal weight (published) | 31 lb/ft |
Values converted exactly from the official AISC Shapes Database v15.0 (identical to v16.0 for this shape). Mass per metre above is computed from cross-sectional area and steel density (7850 kg/m³) — a derived value, not a separately-published table figure.
Related W sections