Aluminum 8090 · temper
Aluminum 8090-O
Properties of the O condition, compared with the other 8090 tempers.
Softest condition, chosen for severe forming, stretch-forming or intermediate processing before solution treatment and aging.
What is 8090-O?
8090-O is 8090 in the O temper — softest condition, chosen for severe forming, stretch-forming or intermediate processing before solution treatment and aging. 8090-O has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 265 MPa (38.4 ksi) — weaker than 71% of aluminum grades. Elongation at break is 14% and the elastic modulus is 78 GPa (11.3 Msi). 8090-O has a density of 2.54 g/cm³ (0.0918 lb/in³), lighter than 100% of aluminum grades. It melts at 600°C (1,112 °F). T851 is the default condition FabDigit quotes; O is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 32 MPa·√m (29.1 ksi·√in), better than 83% of aluminum grades
- Ductile — tolerates forming and impact — 14%, better than 81% of aluminum grades
- Forms and bends easily — 65/100, better than 80% of aluminum grades
Limitations
- High embodied carbon — 14 kg CO₂/kg, worse than 95% of aluminum grades
- Poor heat conductor — 100 W/m·K (57.8 BTU/hr·ft·°F), worse than 93% of aluminum grades
- Low electrical conductivity — 26 % IACS, worse than 90% of aluminum grades
- Difficult to machine — 40/100, worse than 80% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
8090-O properties
Typical room-temperature values for 8090-O — 10 properties are specific to this condition; the rest are grade-level values shared by every 8090 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
8090-O has a density of 2.54 g/cm³ (0.0918 lb/in³), lighter than 100% of aluminum grades. It melts at 600°C (1,112 °F).
Mechanical12
8090-O has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 265 MPa (38.4 ksi) — weaker than 71% of aluminum grades. Elongation at break is 14% and the elastic modulus is 78 GPa (11.3 Msi).
Thermal6
8090-O is rated for continuous service to 120°C (248 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), worse than 93% of aluminum grades. Thermal expansion is 21.4 µm/m·K (11.9 µin/in·°F).
Electrical3
8090-O conducts electricity at 26 % IACS, worse than 90% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of 8090-O takes about 220 MJ of energy and emits 14 kg of CO₂ — more than 95% of aluminum grades. Typical recycled content is 5%.
Manufacturability7
8090-O's machinability is fair (40/100, worse than 80% of aluminum grades); weldability poor (25/100); formability good (65/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 8090 tempers and conditions
8090 is also supplied in 12 other conditions. The full side-by-side table is on the 8090 overview.
- T851DefaultThe workhorse plate temper for machined aerospace structure: peak strength with low residual stress so thick plate machines flat without distortion.425 MPa yield · 135 HB
- T6511Peak-aged 8090 extrusion/bar temper: T651 practice plus permitted minor straightening after stretching, giving high longitudinal strength with strong directional (texture) anisotropy.440 MPa yield · 150 HB
- T8Generic peak-strength Al-Li condition: cold work before aging refines the strengthening precipitates, giving the best strength/stiffness combination.415 MPa yield · 135 HB
- T651Peak-aged 8090 Al-Li plate stretched 1.5–3 % after solution treatment for low residual stress; highest strength-to-density of the 8090 tempers but reduced short-transverse toughness and SCC resistance versus T8771.415 MPa yield · 145 HB
- T8771Proprietary aging practice trading a little yield strength for markedly better fracture toughness and short-transverse ductility in thick sections.390 MPa yield · 130 HB
- T6Peak-aged without stretching; used for forgings and shapes where cold work before aging is impractical, but strength and toughness are below T8 tempers.370 MPa yield · 128 HB
- T7Overaged condition selected when stress-corrosion and exfoliation resistance outweigh maximum strength.350 MPa yield · 120 HB
- OSoftest condition, chosen for severe forming, stretch-forming or intermediate processing before solution treatment and aging.140 MPa yield · 65 HB
Working with 8090-O
Is 8090 easy to machine?
Machines like a hard 2xxx alloy but Zr/Li constituents accelerate tool wear — use sharp carbide/PCD, high speed, generous coolant, and keep fine chips wet since Li-bearing dust is reactive.
Can 8090 be welded?
Fusion welding is problematic (Li oxide film, hydrogen porosity, hot cracking); joints are normally riveted, bonded or friction-stir/electron-beam welded rather than TIG/MIG.
Can 8090 be formed, bent or molded?
Form in O, T3 or T4; T8-type plate has low ductility and pronounced through-thickness anisotropy, so bend radii must be generous and short-transverse loading avoided.
What surface finishes work on 8090?
Chromic or sulfuric anodize plus primer is standard for aerospace corrosion protection; alkaline etch times must be controlled because Li-rich phases dissolve preferentially and can dull the finish.
8090 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 |
|---|---|---|
| Liprincipal density-reducing / δ′ forming element | 2.2 – 2.7 | 2.4 |
| Cu | 1 – 1.6 | 1.3 |
| Mg | 0.6 – 1.3 | 0.9 |
| Zrgrain-structure control | 0.04 – 0.16 | 0.1 |
| Fe | ≤ 0.3 | — |
| Si | ≤ 0.2 | — |
| Mn | ≤ 0.1 | — |
| Cr | ≤ 0.1 | — |
| Zn | ≤ 0.25 | — |
| Ti | ≤ 0.1 | — |
| Others (each)total 0.15 max | ≤ 0.05 | — |
| Al | balance | — |
8090-O — frequently asked
What is 8090-O used for?
8090-O is typically used for aerospace structural components, helicopter airframe parts, fuselage frames and bulkheads, wing ribs and stringers, machined structural fittings and seat tracks and floor structure. In short: low-density Al-Li; aerospace classic.
What is the yield strength of 8090-O?
8090-O has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 265 MPa (38.4 ksi) — weaker than 71% of aluminum grades. Strength varies by condition: see the 13 listed tempers.
Is 8090-O easy to machine?
Not especially — machinability is rated fair (40/100, worse than 80% of aluminum grades). Machines like a hard 2xxx alloy but Zr/Li constituents accelerate tool wear — use sharp carbide/PCD, high speed, generous coolant, and keep fine chips wet since Li-bearing dust is reactive.
Can 8090-O be welded?
Not readily — weldability is rated poor (25/100). Fusion welding is problematic (Li oxide film, hydrogen porosity, hot cracking); joints are normally riveted, bonded or friction-stir/electron-beam welded rather than TIG/MIG.
What surface finishes work on 8090-O?
Chromic or sulfuric anodize plus primer is standard for aerospace corrosion protection; alkaline etch times must be controlled because Li-rich phases dissolve preferentially and can dull the finish.
Can 8090-O be formed, bent or molded?
Form in O, T3 or T4; T8-type plate has low ductility and pronounced through-thickness anisotropy, so bend radii must be generous and short-transverse loading avoided.
What is the maximum service temperature of 8090-O?
8090-O is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 8090-T851 and 8090-O?
T851 is the default condition — the workhorse plate temper for machined aerospace structure: peak strength with low residual stress so thick plate machines flat without distortion. O: softest condition, chosen for severe forming, stretch-forming or intermediate processing before solution treatment and aging. Yield strength is 425 MPa in T851 versus 140 MPa in O.
Can FabDigit make parts in 8090-O?
Yes — 8090-O is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- Aluminum-Lithium Alloys: Processing, Properties and Applications — Elsevier/Butterworth-Heinemann (2014)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Lital A / 8090 plate and sheet property data — British Alcan / Alcan Aerospace (1990)
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.