HSS16X8X5/8 Steel Rectangular HSS — Section Properties

Dimensions

Property Value Unit
Height (h) 16 406.4 mm
Width (w) 8 203.2 mm
Wall Thickness (t) 0.625 15.9 mm
Area (A) 25.7 in² 165.8 cm²
Weight 93.34 lb/ft 138.9 kg/m

Elastic Section Properties

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 815 274 in⁴
Elastic Section Modulus (S) 102 68.6 in³
Plastic Section Modulus (Z) 129 79.2 in³
Radius of Gyration (r) 5.64 3.27 in

Torsional Properties

Property Value Unit
Torsional Constant (J) 681 in⁴
Warping Constant (Cw) 0 in⁶

Section Profile Summary

HSS provides uniform strength in all directions — efficient for columns, bracing, and torsion-critical applications. At 93.34 lb/ft, this section is a practical choice for bracing, secondary columns, and architectural exposed steel.

Key Design Checks (AISC 360)

Check Formula This Section
Plastic moment Mp = Zx × Fy 6,450 kip-in
Deflection Δ = 5wL⁴/(384EIx) Use Ix = 815 in⁴
Torsion St. Venant = GJ/L J = 681 in⁴
Column buckling KL/r → Fcr r_x = 5.64 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 — hss16x8x5-8

Scenario: Wind column between windows in a curtain wall system Unbraced length L = 13 ft.

Given:

Step 1 — Slenderness ratio:

KL/r = 156 / 5.64 = 28

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

Elastic buckling stress: Fe = π²E / (KL/r)² = π² × 29,000 / (28)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 × 25.7 ≈ 1,157 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.