HSS13.375X0.500 Steel Round HSS — Section Properties

Dimensions

Property Value Unit
Outer Diameter (OD) 13.4 340.4 mm
Wall Thickness (t) 0.5 12.7 mm
Area (A) 18.9 in² 121.9 cm²
Weight 68.82 lb/ft 102.4 kg/m

Elastic Section Properties

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 393 393 in⁴
Elastic Section Modulus (S) 58.8 58.8 in³
Plastic Section Modulus (Z) 77.5 77.5 in³
Radius of Gyration (r) 4.57 4.57 in

Torsional Properties

Property Value Unit
Torsional Constant (J) 787 in⁴
Warping Constant (Cw) 0 in⁶

Section Profile Summary

Closed tubular section with J = 787 in⁴ — torsional stiffness is significantly higher than an open section of equivalent weight. The flat faces accept welded gusset and end-plate connections without stiffeners.

Key Design Checks (AISC 360)

Check Formula This Section
Plastic moment Mp = Zx × Fy 3,875 kip-in
Deflection Δ = 5wL⁴/(384EIx) Use Ix = 393 in⁴
Torsion St. Venant = GJ/L J = 787 in⁴
Column buckling KL/r → Fcr r_x = 4.57 in

Design Notes

Verification (AISC 360): All designs using this section must be verified by a licensed Professional Engineer. Before finalizing member selection, check beam-column interaction (P-M), lateral-torsional buckling, serviceability deflections, and all connection limit states. See Engineering Disclaimer.

Worked Example: Column Capacity — hss13_375x0_500

Scenario: Mezzanine column in a warehouse Unbraced length L = 9 ft.

Given:

Step 1 — Slenderness ratio:

KL/r = 108 / 4.57 = 24

Step 2 — Determine critical stress Fcr (AISC 360 Chapter E):

Elastic buckling stress: Fe = π²E / (KL/r)² = π² × 29,000 / (24)² = 497 ksi

For HSS with KL/r ≤ 4.71√(E/Fy) = 4.71√(29,000/50) = 113.4:

If KL/r ≤ 113.4: Fcr = 0.658^(Fy/Fe) × Fy (inelastic buckling) If KL/r > 113.4: Fcr = 0.877Fe (elastic buckling)

Step 3 — Design compressive strength:

φPn = φ × Fcr × Ag = 0.9 × Fcr × 18.9 ≈ 850 kips (preliminary)

For a precise capacity accounting for local buckling and the exact KL/r value, use the Column Capacity Calculator with this section's properties.

Related Resources

Design Resources


Educational reference only. Verify all section properties against the current AISC 360 Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.