6061-T6
Solution treated and artificially aged. Full strength; the standard condition for structural and machined tube.
Heat-treatable structural tube
6061 Aluminium Tube & Pipe
6061 aluminium tube is the general-purpose structural tube of the aluminium world: strong in the T6 temper, weldable, corrosion resistant and available in thousands of sizes as extruded tube, drawn seamless tube and schedule pipe. Metline supplies 6061 round tube and pipe (6061 aluminum tubing) from capillary sizes to large diameters, cut to length and certified to ASTM, AMS or EN standards, to customers worldwide.
- Alloy
- 6061 (Al-Mg-Si-Cu)
- Tempers
- T6, T4, O, T6511
- OD range
- 3 – 500 mm
- Standards
- ASTM B221 · B210 · B241 · EN 755
What is 6061 aluminium tube?
6061 tube is round hollow stock made from the magnesium-silicon alloy 6061 and heat-treated, usually to T6. It offers about twice the strength of 3003 or 6063-T5 tube while remaining easy to weld, bend in softer tempers, machine and anodise.
The same alloy is sold under several product names that buyers sometimes confuse. Extruded tube is pushed through a die and suits most structural work. Drawn seamless tube starts as an extruded hollow and is cold-drawn through a die over a mandrel, giving tighter diameter and wall tolerances, a smoother surface and slightly higher guaranteed strength; it is the route for hydraulic lines, precision sleeves and aircraft tubing. Pipe is tube made to nominal pipe sizes (NPS) and schedules so it fits standard fittings and flanges.
Because 6061 combines strength with good corrosion resistance and weldability, it is the default tube alloy in North America and much of Asia for frames, handrails, scaffolding-type structures, vehicle parts, compressed-air lines and countless machined components. In Europe, 6082 fills the same role; both are covered on this site.
6061 chemical composition (wt %)
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | 0.40 | 0.80 |
| Iron (Fe) | — | 0.70 |
| Copper (Cu) | 0.15 | 0.40 |
| Manganese (Mn) | — | 0.15 |
| Magnesium (Mg) | 0.80 | 1.20 |
| Chromium (Cr) | 0.04 | 0.35 |
| Zinc (Zn) | — | 0.25 |
| Titanium (Ti) | — | 0.15 |
| Others each / total | — | 0.05 / 0.15 |
| Aluminium | Remainder |
Limits are those registered with the Aluminum Association and used in ASTM and EN 573-3. Magnesium and silicon form the Mg2Si precipitates that give the T6 strength; copper adds strength and chromium controls grain structure.
6061 tube properties by temper and product route
Drawn tube is guaranteed to higher minimums than extruded tube because cold drawing refines the structure and tightens wall control. Use the minimum for the route and wall range on your order as the design basis.
| Condition | Tensile strength | Yield strength (0.2 %) | Elongation |
|---|---|---|---|
| O, typical | 125 MPa / 18 ksi | 55 MPa / 8 ksi | 25 % |
| T4, typical | 240 MPa / 35 ksi | 145 MPa / 21 ksi | 22 % |
| T6, typical | 310 MPa / 45 ksi | 276 MPa / 40 ksi | 12 – 17 % |
| T6 extruded tube, ASTM B221 minimum | 260 MPa / 38 ksi | 240 MPa / 35 ksi | 8 – 10 % |
| T6 drawn seamless tube, minimum (B210) | 290 MPa / 42 ksi | 241 MPa / 35 ksi | By wall thickness |
| T6 near welds (design value) | 165 MPa / 24 ksi | — | — |
Physical properties (T6)
- Density
- 2.70 g/cm³
- Elastic modulus
- 68.9 GPa
- Shear strength
- 207 MPa
- Fatigue strength (5×10⁸ cycles)
- 96.5 MPa
- Thermal conductivity
- 167 W/m·K
- Electrical conductivity
- 43 % IACS
- Thermal expansion
- 23.6 µm/m·°C
- Melting range
- 582 – 652 °C
Which 6061 tube temper to order
6061-T6511 / T6510
Stretched after quenching to relieve stress, so tube stays straight and stable when machined. Common on extruded tube for CNC work.
6061-T4
Naturally aged. Bends more easily; parts can be formed and then aged to T6.
6061-O
Annealed for flaring, swaging, spinning and tight bends, followed by heat treatment if strength is needed.
6061 tube standards and equivalents
| Product | Standard | Notes |
|---|---|---|
| Extruded tube | ASTM B221, EN 755-2 / 755-7 / 755-8 | General structural and engineering tube |
| Drawn seamless tube | ASTM B210, AMS 4080 / AMS 4082 | Tight tolerances, aircraft and precision use |
| Hydraulic tube | AMS 4083 | Drawn seamless T6 for fluid lines |
| Seamless pipe and tube | ASTM B241 / ASME SB-241 | Pressure piping, NPS sizes |
| Structural pipe and tube | ASTM B429 | Buildings, handrails, structures |
| International names | EN AW-6061, 3.3211, UNS A96061, JIS A6061TE / TD, IS 65032 |
6061 round tube and pipe sizes
Supply range
- Drawn seamless tube
- OD about 3 – 150 mm, wall 0.3 – 10 mm
- Extruded tube
- OD about 10 – 500 mm, wall 1 – 50 mm
- Pipe
- NPS 1/8 to NPS 12 and larger, Schedule 10, 40 and 80
- Length
- 3 m, 6 m (20 ft) and cut lengths; drawn tube in coils for small sizes
- Finish
- Mill, anodised, polished, brushed or powder coated
Weight in kg/m = π × (OD − wall) × wall × 2.70 / 1000. Section modulus Z is used for bending stress.
| OD × wall (mm) | kg/m | I (cm⁴) | Z (cm³) |
|---|---|---|---|
| 10 × 1 | 0.076 | 0.03 | 0.06 |
| 12 × 1 | 0.093 | 0.05 | 0.09 |
| 16 × 1.5 | 0.184 | 0.18 | 0.23 |
| 20 × 2 | 0.305 | 0.46 | 0.46 |
| 25 × 2 | 0.390 | 0.96 | 0.77 |
| 30 × 3 | 0.687 | 2.35 | 1.56 |
| 40 × 3 | 0.942 | 6.01 | 3.00 |
| 50 × 3 | 1.196 | 12.28 | 4.91 |
| 50 × 5 | 1.909 | 18.11 | 7.25 |
| 60 × 4 | 1.900 | 27.73 | 9.24 |
| 80 × 5 | 3.181 | 83.20 | 20.80 |
| 100 × 5 | 4.029 | 168.81 | 33.76 |
| 120 × 10 | 9.331 | 527.00 | 87.83 |
| 150 × 10 | 11.875 | 1083.06 | 144.41 |
| 200 × 15 | 23.538 | 3754.15 | 375.42 |
Schedule pipe weights (ASTM B241 dimensions):
| NPS | OD (mm) | Sch 40 wall | Sch 40 kg/m | Sch 80 wall | Sch 80 kg/m |
|---|---|---|---|---|---|
| 1/2 | 21.3 | 2.77 | 0.44 | 3.73 | 0.56 |
| 3/4 | 26.7 | 2.87 | 0.58 | 3.91 | 0.76 |
| 1 | 33.4 | 3.38 | 0.86 | 4.55 | 1.11 |
| 1-1/2 | 48.3 | 3.68 | 1.39 | 5.08 | 1.86 |
| 2 | 60.3 | 3.91 | 1.87 | 5.54 | 2.57 |
| 3 | 88.9 | 5.49 | 3.88 | 7.62 | 5.25 |
| 4 | 114.3 | 6.02 | 5.53 | 8.56 | 7.68 |
| 6 | 168.3 | 7.11 | 9.72 | 10.97 | 14.64 |
| 8 | 219.1 | 8.18 | 14.63 | 12.7 | 22.23 |
Tolerances and testing
Extruded tube follows the ANSI H35.2 tables (ASTM orders) or EN 755-7 for seamless and EN 755-8 for porthole tube. Drawn tube is held to the tighter B210 or EN 754-7 tables; typical OD tolerance on small drawn tube is a few hundredths of a millimetre. Straightness, ovality and wall eccentricity matter for precision sleeves and hydraulic fittings, so state limits on the drawing when standard tables are not enough.
Inspection options
- Standard
- Dimensions, surface, tensile test per lot, mill test certificate EN 10204 3.1
- Pressure duty
- Hydrostatic test, flattening and flare tests where the specification calls for them
- Critical parts
- Eddy-current or ultrasonic inspection and third-party witness
Bending, welding, machining and finishing
Bending
T6 tube bends to a centreline radius of roughly 3 – 5 × OD on a mandrel bender, depending on wall. For tighter radii, bend in O or T4 and age afterwards.
Welding
TIG or MIG with ER4043 (crack-resistant) or ER5356 (stronger fillets, better anodise match). Expect reduced strength in the heat-affected zone.
Machining
Turns and bores well in T6 with sharp carbide tools; T6511 keeps long sleeves straight after boring.
End forming
Flaring, beading and swaging are best done in O or T4 temper.
Finishing
Anodises clear or coloured, hard-anodises for wear, and accepts powder coating.
Joining to steel
Isolate from steel or stainless fittings with washers or sealant to avoid galvanic corrosion.
Applications of 6061 tube and pipe
- Structures: handrails, guard rails, scaffold-type frames, canopies and space frames
- Transport: truck and trailer components, roll cages for light vehicles, bicycle frames and motorcycle parts
- Fluid systems: compressed-air lines, hydraulic and fuel lines, irrigation pipe
- Marine: bimini frames, rails, masts for small craft and outriggers
- Machinery: rollers, shafts, pneumatic cylinder bodies, spacers and sleeves
- Aerospace ground equipment: stands, tow bars and fixtures
- Sport and medical: wheelchair frames, crutches, tent poles, telescopic poles and fitness equipment
6061 tube compared with 6063, 6082 and 7075
| 6061-T6 | 6063-T6 | 6082-T6 | 7075-T6 | |
|---|---|---|---|---|
| Typical yield | 276 MPa | 214 MPa | 260 – 310 MPa | 505 MPa |
| Weldable | Yes | Yes | Yes | Not recommended |
| Surface finish | Good | Excellent | Good | Fair |
| Drawn seamless availability | Wide | Wide | Moderate | Moderate |
| Typical use | Structural, fluid lines | Architectural, furniture | European structural | Highly stressed parts |
How to order 6061 tube
- SpecifyAlloy and temper (for example 6061-T6 drawn seamless, 25 × 2 mm), section size and wall thickness, length, quantity and the governing standard (ASTM B210, B221, B241 or EN 755-2). A drawing helps for cut parts.
- QuoteWe confirm availability, tolerances, certification and delivery terms (EXW, FOB, CIF or DAP) for your destination.
- ProcessMaterial is cut to length, de-burred and, if you ask, bent, machined or finished before packing.
- DocumentEach shipment carries a mill test certificate to EN 10204 3.1 with chemistry and tensile results, plus the packing list. Third-party inspection can be arranged.
- ShipBundled with end caps and interleaving or packed in seaworthy wooden cases, then shipped by sea or air.
References and standards
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- ASTM B210/B210M – Aluminum and Aluminum-Alloy Drawn Seamless Tubes
- ASTM B241/B241M – Aluminum and Aluminum-Alloy Seamless Pipe and Seamless Extruded Tube
- EN 755-2 – Extruded rod/bar, tubes and profiles: mechanical properties (with EN 755-7 / -8 / -9 dimensional tolerances)
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
6061 aluminium (aluminum) tube: frequently asked questions
What is the difference between extruded and drawn 6061 tube?
Extruded tube is pushed through a die and suits structural work. Drawn seamless tube is extruded and then cold-drawn over a mandrel, giving tighter tolerances, a smoother surface and a higher minimum tensile strength (290 MPa against 260 MPa in T6).
How much does 6061 tube weigh per metre?
Use π × (OD − wall) × wall × 2.70 / 1000. A 50 × 3 mm tube weighs about 1.20 kg/m and a 25 × 2 mm tube about 0.39 kg/m.
Can 6061-T6 tube be bent?
Yes, on a mandrel bender with a centreline radius of roughly 3 – 5 times the OD. Tight bends risk cracking in T6; bend in O or T4 temper and age to T6 afterwards if needed.
Is 6061 pipe suitable for pressure service?
Seamless 6061-T6 pipe to ASTM B241 / ASME SB-241 is used for pressure piping, compressed air and process lines. Porthole (structural) tube should not be used for pressure unless the specification allows it.
What is the European equivalent of 6061 tube?
EN AW-6061 to EN 755-2. Many European designs specify 6082-T6 tube instead, which has similar or slightly higher strength.
Do you export 6061 tube?
Yes. Metline supplies 6061 tube and pipe worldwide with mill test certificates and export packing.
Need 6061 tube or pipe?
Tell us the product route, OD, wall, temper, length and destination, and we will quote availability, certification and freight.
