Aluminum 2020
AA 2020 · UNS A92020
2020 is an early Al-Cu-Li alloy (UNS A92020) developed for high-stiffness aerospace skins, using copper and lithium precipitation hardening to reach an elastic modulus of 76 GPa.
Reference datasheet — 2020 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the T651 condition
2020 tempers and conditions
2020 is supplied in 5 conditions, soft to hard. T651 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Soft interim condition for forming or machining before solution treatment; not a service temper. | 105 | 215 | 14 | 55 HB | 45 % IACS |
Solution heat treated and naturally aged | As-quenched/naturally aged interim state used only between quench and forming or artificial ageing; 2020 develops little strength without artificial ageing. | 235 | 370 | 10 | 100 HB | 30 % IACS |
Solution heat treated and artificially aged | Peak-strength, peak-stiffness condition for extrusions, sheet and forgings; use where static strength/modulus govern and toughness does not. | 525 | 580 | 5 | 150 HB | 33 % IACS |
T6, stress relieved by stretching, minor straightening | Extruded-shape equivalent of T651 where minor straightening after stretching is allowed; chosen for stiff stringers and spar caps. | 525 | 575 | 5 | 148 HB | 33 % IACS |
T651Default T6, stress relieved by stretching | The historically standard plate condition: T6 strength with stretch stress-relief for dimensional stability after machining of skins and panels. | 530 | 580 | 4 | 150 HB | 33 % IACS |
What is 2020?
2020 is an early Al-Cu-Li alloy (UNS A92020) developed for high-stiffness aerospace skins, using copper and lithium precipitation hardening to reach an elastic modulus of 76 GPa. In the default aged condition it provides 530 MPa yield, 580 MPa tensile strength and 150 HB, and it was supplied as sheet and plate in O, T4, T6, T651 and T6511 tempers. Limits are severe: 4 % elongation makes it notch-sensitive, it is effectively not fusion weldable, service is capped near 150 °C and thermal conductivity is 140 W/m·K at 33 % IACS. The alloy is largely obsolete because of its processing sensitivity; specify a third-generation Al-Cu-Li such as 2050 or 2055 for new work. 2020 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 510°C (950 °F). 2020 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 97% of aluminum grades. Elongation at break is 4% and the elastic modulus is 76 GPa (11 Msi).
What is 2020 used for?
- Historic aircraft skin panels
- Stiffness-critical airframe skins
- Aerospace research and comparison stock
- Legacy airframe repair and replacement plate
- Machined stiffeners and doublers on older airframes
- Test coupons for Al-Cu-Li property studies
Advantages
- High strength — 530 MPa (76.9 ksi), better than 97% of aluminum grades
Limitations
- Needs corrosion protection — 28/100, worse than 99% of aluminum grades
- Difficult to weld — 15/100, worse than 96% of aluminum grades
2020 properties
Typical room-temperature values for 2020-T651; bars are the position among aluminum grades.
Physical3
2020 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 510°C (950 °F).
Mechanical11
2020 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 97% of aluminum grades. Elongation at break is 4% and the elastic modulus is 76 GPa (11 Msi).
Thermal6
2020 is rated for continuous service to 150°C (302 °F). It conducts heat at 140 W/m·K (80.9 BTU/hr·ft·°F), worse than 52% of aluminum grades. Thermal expansion is 22.5 µm/m·K (12.5 µin/in·°F).
Electrical3
2020 conducts electricity at 33 % IACS, worse than 57% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (28/100), worse than 99% of aluminum grades.
Sustainability4
Producing a kilogram of 2020 takes about 205 MJ of energy and emits 13 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 0%.
Manufacturability8
2020's machinability is good (62/100, better than 55% of aluminum grades); weldability poor (15/100); formability poor (20/100).
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. 2020 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 2020
Is 2020 easy to machine?
Machines like a hard 2000-series-T6 with good chip control, but the low ductility makes it notch-sensitive — use sharp carbide tools, generous radii and avoid sharp re-entrant corners.
Can 2020 be welded?
Effectively not fusion weldable: lithium causes oxide entrapment and porosity and the Cu-Li composition is hot-crack prone; joints were riveted or bonded, with FSW the only modern option.
Can 2020 be formed, bent or molded?
Form in the O or freshly quenched condition only; T6/T651 material has 3-6 % elongation and low short-transverse ductility, so cold bending and stretch forming of aged plate should be avoided.
2020 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 |
|---|---|---|
| Cu | 4 – 5 | 4.5 |
| Liprincipal density-reducing / stiffness-raising addition | 0.9 – 1.7 | 1.2 |
| Mn | 0.3 – 0.8 | 0.5 |
| Cdageing accelerator; toxicity in melting was a major drawback | 0.1 – 0.3 | 0.2 |
| Siimpurity limit | ≤ 0.4 | |
| Feimpurity limit | ≤ 0.4 | |
| Others (each)total 0.15 max | ≤ 0.05 | |
| Al | balance |
What surface finishes work on 2020?
Clad, chromic-acid anodize or conversion-coat plus primer for corrosion protection; bare surfaces pit readily and sulphuric anodizing gives a dull grey film due to Cu and Li.
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).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 2020 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A92020
How much does 2020 cost?
2020 is a high-cost aluminum ($$$$), pricier than about 78% 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.
2020 — frequently asked
What is 2020 used for?
2020 is typically used for historic aircraft skin panels, stiffness-critical airframe skins, aerospace research and comparison stock, legacy airframe repair and replacement plate, machined stiffeners and doublers on older airframes and test coupons for Al-Cu-Li property studies. In short: obsolete Al-Cu-Li skin alloy; high stiffness, low ductility; riveted or bonded only.
What is the yield strength of 2020?
2020 has a typical yield strength of 530 MPa (76.9 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 97% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is 2020 easy to machine?
Reasonably — machinability is rated good (62/100, better than 55% of aluminum grades). Machines like a hard 2000-series-T6 with good chip control, but the low ductility makes it notch-sensitive — use sharp carbide tools, generous radii and avoid sharp re-entrant corners.
Can 2020 be welded?
Not readily — weldability is rated poor (15/100). Effectively not fusion weldable: lithium causes oxide entrapment and porosity and the Cu-Li composition is hot-crack prone; joints were riveted or bonded, with FSW the only modern option.
What surface finishes work on 2020?
Clad, chromic-acid anodize or conversion-coat plus primer for corrosion protection; bare surfaces pit readily and sulphuric anodizing gives a dull grey film due to Cu and Li.
Can 2020 be formed, bent or molded?
Form in the O or freshly quenched condition only; T6/T651 material has 3-6 % elongation and low short-transverse ductility, so cold bending and stretch forming of aged plate should be avoided.
What is the maximum service temperature of 2020?
2020 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.
What is the difference between 2020-T651 and 2020-O?
T651 is the default condition — the historically standard plate condition: T6 strength with stretch stress-relief for dimensional stability after machining of skins and panels. O: soft interim condition for forming or machining before solution treatment; not a service temper. Yield strength is 530 MPa in T651 versus 105 MPa in O.
How much does 2020 cost?
2020 is a high-cost aluminum ($$$$), pricier than about 78% 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.
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 and Special-Purpose Materials — ASM International (1990)
- Aluminum-Lithium Alloys: Processing, Properties and Applications — Elsevier / Butterworth-Heinemann (2014)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- MMPDS / MIL-HDBK-5 historical aluminum alloy data — Battelle / FAA (2022)
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.