HSS22X20X1/2 Steel Rectangular HSS — Section Properties

Dimensions

Property Value Unit
Height (h) 22 558.8 mm
Width (w) 20 508.0 mm
Wall Thickness (t) 0.5 12.7 mm
Area (A) 37.6 in² 242.6 cm²
Weight 137.3 lb/ft 204.3 kg/m

Elastic Section Properties

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 2820 2440 in⁴
Elastic Section Modulus (S) 256 244 in³
Plastic Section Modulus (Z) 297 279 in³
Radius of Gyration (r) 8.65 8.04 in

Torsional Properties

Property Value Unit
Torsional Constant (J) 4060 in⁴
Warping Constant (Cw) 0 in⁶

Section Profile Summary

Closed tubular section with J = 4,060 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 14,850 kip-in
Deflection Δ = 5wL⁴/(384EIx) Use Ix = 2,820 in⁴
Torsion St. Venant = GJ/L J = 4,060 in⁴
Column buckling KL/r → Fcr r_x = 8.65 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 — hss22x20x1-2

Scenario: Exterior column in a 5-story moment frame Unbraced length L = 8 ft.

Given:

Step 1 — Slenderness ratio:

KL/r = 96 / 8.65 = 11

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

Elastic buckling stress: Fe = π²E / (KL/r)² = π² × 29,000 / (11)² = 2,365 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 × 37.6 ≈ 1,692 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.