HSS8x8x5/8 — Dimensions, Weight & Section Properties
Hollow structural section per ASTM A500 / AISC Steel Construction Manual
HSS8x8x5/8 is an American hollow structural section (HSS) 8×8 inches (203.2×203.2 mm) with a nominal 0.625 in wall, weighing 59.32 pounds per foot (88.3 kg/m). Section properties below are the AISC published values, computed with the A500 design wall thickness of 0.93×nominal — with metric equivalents alongside.
Typical uses: columns, braces, truss members, equipment frames, and architectural steel — closed sections excel in compression and torsion and take paint beautifully. For a quick stiffness check, see the deflection example below or open the beam calculator with your own span and load.
Dimensions
| Height h | 8 in (203.2 mm) |
| Width b | 8 in (203.2 mm) |
| Nominal wall t | 0.625 in (15.9 mm) |
| Design wall (0.93t) | 0.581 in (14.8 mm) |
Weight & Cross-Section
| Weight per foot | 59.32 lb/ft (88.3 kg/m) |
| 20 ft bar | 1,186 lb |
| 40 ft bar | 2,373 lb |
| Area A | 16.4 in² (105.8 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 146 in⁴ (6,077 cm⁴) |
| Section modulus Sx | 36.5 in³ (598 cm³) |
| Radius of gyration rx | 2.99 in |
| Moment of inertia Iy | 146 in⁴ (6,077 cm⁴) |
| Section modulus Sy | 36.5 in³ (598 cm³) |
| Radius of gyration ry | 2.99 in |
Compared with the neighbouring sizes
| Shape | h × b (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| HSS8x8x1/2 | 8 × 8 | 48.85 | 125 | 31.2 | −18 % | −14 % |
| HSS8x8x5/8 (this page) | 8 × 8 | 59.32 | 146 | 36.5 | — | — |
Deflection example
A simply supported HSS8x8x5/8 spanning 13 ft with a 10 kip point load at midspan deflects 0.19 in (E = 29,000 ksi, Ix = 146 in⁴). The L/360 serviceability limit for this span is 0.43 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a HSS8x8x5/8 tube weigh?
HSS8x8x5/8 weighs 59.32 pounds per foot (88.3 kg/m). A 20 ft bar weighs 1,186 lb and a 40 ft bar 2,373 lb.
What are the dimensions of a HSS8x8x5/8?
HSS8x8x5/8 is 8×8 in (203.2×203.2 mm) outside, with a nominal wall of 0.625 in. Note that A500 tolerances put the design wall at 0.93×nominal (0.581 in) — the section properties listed already account for this.
What are the dimensions of a HSS8x8x5/8 in mm?
HSS8x8x5/8 is 203.2×203.2 mm outside with a nominal wall of 15.9 mm. In metric section properties: Ix = 6,077 cm⁴, Sx = 598 cm³.
How much does a HSS8x8x5/8 weigh in kg?
88.3 kg per meter. A 6 m bar weighs 530 kg and a 12 m bar 1,059 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a HSS8x8x5/8?
About the strong axis, Ix = 146 in⁴ (6,077 cm⁴) with section modulus Sx = 36.5 in³. About the weak axis, Iy = 146 in⁴ and Sy = 36.5 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
HSS8x8x5/8 or HSS8x8x1/2 — what does one size down change?
HSS8x8x1/2 is about 18% lighter (48.85 vs 59.32 lb/ft) but about 14% less stiff (Ix 125 vs 146 in⁴). Check deflection before downsizing — stiffness falls much faster than weight.
Values are entered from the governing standard’s published tables and cross-checked programmatically against its mass and section formulas before publication. Spotted an error? Write to advertising@metalabout.net — verified corrections ship within days. About