HSS8x8x3/8 — Dimensions, Weight & Section Properties
Hollow structural section per ASTM A500 / AISC Steel Construction Manual
HSS8x8x3/8 is an American hollow structural section (HSS) 8×8 inches (203.2×203.2 mm) with a nominal 0.375 in wall, weighing 37.69 pounds per foot (56.1 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 | 0.375 in (9.5 mm) |
| Design wall (0.93t) | 0.349 in (8.9 mm) |
Weight & Cross-Section
| Weight per foot | 37.69 lb/ft (56.1 kg/m) |
| 20 ft bar | 754 lb |
| 40 ft bar | 1,508 lb |
| Area A | 10.4 in² (67.1 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 100 in⁴ (4,162 cm⁴) |
| Section modulus Sx | 25.1 in³ (411 cm³) |
| Radius of gyration rx | 3.1 in |
| Moment of inertia Iy | 100 in⁴ (4,162 cm⁴) |
| Section modulus Sy | 25.1 in³ (411 cm³) |
| Radius of gyration ry | 3.1 in |
Compared with the neighbouring sizes
| Shape | h × b (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| HSS8x8x1/4 | 8 × 8 | 25.82 | 70.7 | 17.7 | −31 % | −29 % |
| HSS8x8x3/8 (this page) | 8 × 8 | 37.69 | 100 | 25.1 | — | — |
| HSS8x8x1/2 | 8 × 8 | 48.85 | 125 | 31.2 | +30 % | +25 % |
Deflection example
A simply supported HSS8x8x3/8 spanning 13 ft with a 10 kip point load at midspan deflects 0.27 in (E = 29,000 ksi, Ix = 100 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 HSS8x8x3/8 tube weigh?
HSS8x8x3/8 weighs 37.69 pounds per foot (56.1 kg/m). A 20 ft bar weighs 754 lb and a 40 ft bar 1,508 lb.
What are the dimensions of a HSS8x8x3/8?
HSS8x8x3/8 is 8×8 in (203.2×203.2 mm) outside, with a nominal wall of 0.375 in. Note that A500 tolerances put the design wall at 0.93×nominal (0.349 in) — the section properties listed already account for this.
What are the dimensions of a HSS8x8x3/8 in mm?
HSS8x8x3/8 is 203.2×203.2 mm outside with a nominal wall of 9.5 mm. In metric section properties: Ix = 4,162 cm⁴, Sx = 411 cm³.
How much does a HSS8x8x3/8 weigh in kg?
56.1 kg per meter. A 6 m bar weighs 337 kg and a 12 m bar 673 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a HSS8x8x3/8?
About the strong axis, Ix = 100 in⁴ (4,162 cm⁴) with section modulus Sx = 25.1 in³. About the weak axis, Iy = 100 in⁴ and Sy = 25.1 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
HSS8x8x3/8 or HSS8x8x1/2 — what does one size up change?
HSS8x8x1/2 is about 30% heavier (48.85 vs 37.69 lb/ft) but about 25% stiffer (Ix 125 vs 100 in⁴). Going one step up within the same depth group is usually the cheapest way to cut deflection.
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