Aluminum 6069-O (Annealed)
Temper
AA 6069 · UNS A96069
Softest condition for severe forming, bending or machining before heat treatment.
Values for the O condition
Other 6069 tempers and conditions
6069 is listed in 7 conditions; see the grade overview at 6069.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OThis page Annealed | Softest condition for severe forming, bending or machining before heat treatment. | 75 | 150 | 25 | 45 HB | 48 % IACS |
Solution heat treated and naturally aged | Choose when parts must be formed or bent after solution treatment and later artificially aged to T6. | 180 | 295 | 20 | 80 HB | 42 % IACS |
Cooled from hot working and artificially aged | Press-quenched extrusions where full solution treatment is skipped for cost and distortion control. | 325 | 360 | 10 | 105 HB | 41 % IACS |
Solution heat treated and overaged (stabilized) | Overaged condition traded for better dimensional stability, corrosion resistance and toughness at ~10 % lower strength. | 330 | 370 | 13 | 108 HB | 44 % IACS |
T6Default Solution heat treated and artificially aged | Standard stocked condition: maximum strength for structural extrusions, tube and machined parts. | 380 | 415 | 12 | 120 HB | 40 % IACS |
T6, stress relieved by stretching | Plate and rolled bar for machined parts that must stay flat after heavy stock removal. | 380 | 415 | 11 | 120 HB | 40 % IACS |
T6, stress relieved by stretching, minor straightening | Standard extruded bar/profile temper where straightness and low residual stress matter for machining. | 385 | 420 | 12 | 122 HB | 40 % IACS |
What is 6069-O?
6069-O is 6069 in the O temper — softest condition for severe forming, bending or machining before heat treatment. 6069-O has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 150 MPa (21.8 ksi) — weaker than 91% of aluminum grades. Elongation at break is 25% and the elastic modulus is 69.5 GPa (10.1 Msi). 6069-O has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 580°C (1,076 °F). T6 is the default condition FabDigit quotes; O is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 25%, better than 94% of aluminum grades
- Forms and bends easily — 85/100, better than 91% of aluminum grades
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
- Conducts heat well — 190 W/m·K (109.8 BTU/hr·ft·°F), better than 89% of aluminum grades
- High electrical conductivity — 48 % IACS, better than 88% of aluminum grades
Limitations
- Low strength — 75 MPa (10.9 ksi), worse than 91% of aluminum grades
- Difficult to machine — 35/100, worse than 86% of aluminum grades
6069-O properties
Typical room-temperature values for 6069-O; 11 are specific to this condition. Other listed values are 6069 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
6069-O has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 580°C (1,076 °F).
Mechanical16
6069-O has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 150 MPa (21.8 ksi) — weaker than 91% of aluminum grades. Elongation at break is 25% and the elastic modulus is 69.5 GPa (10.1 Msi).
Thermal6
6069-O is rated for continuous service to 200°C (392 °F). It conducts heat at 190 W/m·K (109.8 BTU/hr·ft·°F), better than 89% of aluminum grades. Thermal expansion is 23.2 µm/m·K (12.9 µin/in·°F).
Electrical3
6069-O conducts electricity at 48 % IACS, better than 88% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of 6069-O takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
6069-O's machinability is fair (35/100, worse than 86% of aluminum grades); weldability very good (70/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6069-O
Is 6069 easy to machine?
Machines like a stiffer 6061-T6: high SFM with polished-flute carbide, flood coolant or MQL, chips break better in T6 than in T4/O.
Can 6069 be welded?
GTAW/GMAW with 4043 or 4643 filler is routine, but expect HAZ softening to near-T4 strength unless the assembly is re-solution-treated and aged; avoid pure Al filler.
Can 6069 be formed, bent or molded?
Form, bend or hydroform in O or T4 and age afterwards; T6 tube bending needs generous radii (≥3×D) and mandrel support to avoid cracking.
What surface finishes work on 6069?
Responds well to sulfuric clear and hardcoat anodize (slightly darker/greyer than 6061 from Cu+Si); chromate/Ti-Zr conversion coats and powder paint work normally, and Cu content makes protective coating advisable in marine service.
6069 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 | 0.6 – 1.2 | 0.9 |
| Feimpurity limit | ≤ 0.35 | 0.15 |
| Cumain strength addition vs 6061 | 0.5 – 0.9 | 0.7 |
| Mndispersoid former, grain control | 0.2 – 0.8 | 0.4 |
| Mg | 0.8 – 1.2 | 1 |
| Cr | ≤ 0.3 | 0.15 |
| Zn | ≤ 0.25 | 0.05 |
| Tigrain refiner | ≤ 0.15 | 0.03 |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
6069-O — frequently asked
What is 6069-O used for?
6069-O is typically used for high-strength structural extrusions, aerospace fittings and brackets, load-bearing tube and profile, machined structural hardware, transport frame members and bent tubular structures. In short: stronger than 6061-T6; weldable high-strength 6000 series; copper lowers corrosion resistance.
What is the yield strength of 6069-O?
6069-O has a typical yield strength of 75 MPa (10.9 ksi) and a tensile strength of 150 MPa (21.8 ksi) — weaker than 91% of aluminum grades. Strength varies by condition: see the 7 listed tempers.
Is 6069-O easy to machine?
Not especially — machinability is rated fair (35/100, worse than 86% of aluminum grades). Machines like a stiffer 6061-T6: high SFM with polished-flute carbide, flood coolant or MQL, chips break better in T6 than in T4/O.
Can 6069-O be welded?
Yes — weldability is rated very good (70/100). GTAW/GMAW with 4043 or 4643 filler is routine, but expect HAZ softening to near-T4 strength unless the assembly is re-solution-treated and aged; avoid pure Al filler.
What surface finishes work on 6069-O?
Responds well to sulfuric clear and hardcoat anodize (slightly darker/greyer than 6061 from Cu+Si); chromate/Ti-Zr conversion coats and powder paint work normally, and Cu content makes protective coating advisable in marine service.
Can 6069-O be formed, bent or molded?
Form, bend or hydroform in O or T4 and age afterwards; T6 tube bending needs generous radii (≥3×D) and mandrel support to avoid cracking.
What is the maximum service temperature of 6069-O?
6069-O is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 6069-T6 and 6069-O?
T6 is the default condition — standard stocked condition: maximum strength for structural extrusions, tube and machined parts. O: softest condition for severe forming, bending or machining before heat treatment. Yield strength is 380 MPa in T6 versus 75 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- MMPDS-17 typical property data for 6000-series wrought alloys — Battelle/FAA (2022)
- High-strength 6069 extrusion product literature — Aluminum extruder (Alcoa/Universal Alloy lineage) (2015)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.