Aluminum 6066
AA 6066 · UNS A96066 · EN AW-6066, AW 6066
6066 is a copper- and manganese-bearing Al-Mg-Si alloy (UNS A96066) in the heat-treatable 6000-series family, alloyed more heavily than 6061 to reach higher strength in T6/T651.
6066 tempers and conditions
6066 is supplied in 11 conditions, soft to hard.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for severe forming or machining of complex blanks before solution treating to T6. | 83 | 150 | 18 | 43 HB | 43 % IACS |
Solution heat treated and naturally aged by the user | Same metallurgy as T4 but heat treated by the fabricator after forming; slightly lower guaranteed properties. | 200 | 355 | 16 | 88 HB | 37 % IACS |
Solution heat treated and naturally aged | Medium-strength, more ductile condition for bending/forming of extrusions that will later be aged to T6 or used as-is. | 205 | 360 | 18 | 90 HB | 37 % IACS |
T4, stress relieved by stretching | T4 with a controlled stretch to relieve residual stress — pick for flat, low-distortion machining stock in the naturally aged condition. | 205 | 360 | 17 | 90 HB | 37 % IACS |
T4, stress relieved by stretching, no further straightening | Extruded T4 stress-relieved product supplied without post-stretch straightening; used where minor bow is acceptable. | 205 | 360 | 17 | 90 HB | 37 % IACS |
T4, stress relieved by stretching with minor straightening | Same as T4510 but minor straightening is permitted for tighter straightness tolerances on long extrusions. | 205 | 360 | 17 | 90 HB | 37 % IACS |
T6, heat treated by the user | Re-heat-treated to T6-level strength after forming or welding by the fabricator, when incoming material was O/F/T4. | 350 | 390 | 11 | 118 HB | 40 % IACS |
Solution heat treated and artificially aged | Standard peak-strength condition for structural extrusions, forgings and machined hydraulic/mechanical parts needing more strength than 6061-T6. | 359 | 395 | 12 | 120 HB | 40 % IACS |
T6, stress relieved by stretching | T6 stress-relieved stock for precision machined parts where distortion after material removal must be minimised. | 359 | 395 | 12 | 120 HB | 40 % IACS |
T6, stress relieved by stretching, no further straightening | Most common stress-relieved extrusion temper for long T6 profiles machined all over. | 359 | 395 | 12 | 120 HB | 40 % IACS |
T6, stress relieved by stretching, minor straightening | T6510 with limited straightening allowed — choose for tight straightness on bar and complex profiles. | 359 | 395 | 12 | 120 HB | 40 % IACS |
What is 6066?
6066 is a copper- and manganese-bearing Al-Mg-Si alloy (UNS A96066) in the heat-treatable 6000-series family, alloyed more heavily than 6061 to reach higher strength in T6/T651. Engineers specify it for heavy forgings, extruded structural sections and machined parts that need 6000-series-type corrosion behaviour with more load capacity; it is available in T4, T6, T42, T451, T62, T651 and stress-relieved T4510/T4511/T6510/T6511 forms. The copper content discourages arc welding and raises intergranular corrosion risk, and bright decorative anodizing is poor, so use 6061 or 6063 where welding or cosmetic finish governs. 6066 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 563°C (1,045 °F). 6066 has a yield strength of 359 MPa (52.1 ksi) and a tensile strength of 395 MPa (57.3 ksi) — stronger than 84% of aluminum grades. Elongation at break is 12% and the elastic modulus is 69 GPa (10 Msi).
What is 6066 used for?
- Forged shafts
- Cycle rims
- Heavy extruded structural sections
- High-strength machined brackets
- Forged suspension and linkage parts
- Hydraulic and pneumatic bodies
Advantages
- High strength — 359 MPa (52.1 ksi), better than 84% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
6066 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
6066 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 563°C (1,045 °F).
Mechanical11
6066 has a yield strength of 359 MPa (52.1 ksi) and a tensile strength of 395 MPa (57.3 ksi) — stronger than 84% of aluminum grades. Elongation at break is 12% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6066 is rated for continuous service to 150°C (302 °F). It conducts heat at 147 W/m·K (84.9 BTU/hr·ft·°F), better than 55% of aluminum grades. Thermal expansion is 23.2 µm/m·K (12.9 µin/in·°F).
Electrical3
6066 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of 6066 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 30%.
Manufacturability6
6066's machinability is very good (72/100, better than 80% of aluminum grades); weldability fair (40/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. 6066 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 6066
Is 6066 easy to machine?
One of the better-machining 6000-series alloys thanks to Cu and Mn — sharp polished-flute carbide tools, high speed, chip-clearing coolant; T6/T651 gives cleaner chips than T4.
Can 6066 be welded?
Arc welding is discouraged (Cu-bearing, hot-crack and IGC prone); if required use 4043/4145 filler, low heat input and re-heat-treat plus age, expecting a weak HAZ.
Can 6066 be formed, bent or molded?
Extrudes and forges well at 400–480 °C but cold formability in T6 is poor — bend and cold-form in O or T4 and age afterwards.
Manufacturability
The process limits FabDigit applies to 6066. Every 6066 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better72 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Not Recommend30 / 100 |
|---|---|
| Weldability | Fair40 / 100 |
6066 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Si | 0.9 – 1.8 | 1.4 |
| Fe | ≤ 0.5 | |
| Cu | 0.7 – 1.2 | 0.95 |
| Mn | 0.6 – 1.1 | 0.8 |
| Mg | 0.8 – 1.4 | 1.1 |
| Cr | ≤ 0.4 | |
| Zn | ≤ 0.25 | |
| Ti | ≤ 0.2 | |
| Others (each)each | ≤ 0.05 | |
| Others (total)total | ≤ 0.15 | |
| Al | balance |
What surface finishes work on 6066?
Takes hard sulfuric and chromic anodize well and paints/powder-coats readily; Cu makes clear/bright decorative anodize gray and blotchy, so specify architectural finish on 6061/6063 instead.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 6066 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A96066
- Aluminum Association
- AA6066
- EN / DIN / Werkstoff-Nr.
- AW-6066AW 6066
How much does 6066 cost?
6066 is a standard-cost aluminum ($$), cheaper than about 80% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
6066 — frequently asked
What is 6066 used for?
6066 is typically used for forged shafts, cycle rims, heavy extruded structural sections, high-strength machined brackets, forged suspension and linkage parts and hydraulic and pneumatic bodies. In short: high-strength forging alloy.
What is the yield strength of 6066?
6066 has a typical yield strength of 359 MPa (52.1 ksi) and a tensile strength of 395 MPa (57.3 ksi) — stronger than 84% of aluminum grades. Strength varies by condition: see the 11 listed tempers.
Is 6066 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). One of the better-machining 6000-series alloys thanks to Cu and Mn — sharp polished-flute carbide tools, high speed, chip-clearing coolant; T6/T651 gives cleaner chips than T4.
Can 6066 be welded?
With care — weldability is rated fair (40/100). Arc welding is discouraged (Cu-bearing, hot-crack and IGC prone); if required use 4043/4145 filler, low heat input and re-heat-treat plus age, expecting a weak HAZ.
What surface finishes work on 6066?
Takes hard sulfuric and chromic anodize well and paints/powder-coats readily; Cu makes clear/bright decorative anodize gray and blotchy, so specify architectural finish on 6061/6063 instead.
Can 6066 be formed, bent or molded?
Extrudes and forges well at 400–480 °C but cold formability in T6 is poor — bend and cold-form in O or T4 and age afterwards.
What is the maximum service temperature of 6066?
6066 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 6066 cost?
6066 is a standard-cost aluminum ($$), cheaper than about 80% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 6066?
Yes — 6066 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- Aluminum Association International Alloy Designations and Chemical Composition Limits (Teal Sheets) — The Aluminum Association (2018)
- ASTM B221 — Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles and Tubes — ASTM International (2021)
- EN 573-3 / EN 755-2 — Wrought aluminium alloys, composition and extruded product properties — CEN (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Aluminum Standards and Data (typical mechanical & physical property tables) — The Aluminum Association (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.