Aluminum 2A90-O (Annealed)
Temper
GB 2A90
Use the annealed state for forging blanks or wherever maximum plasticity (18% elongation, 60 HB) is required before re-solution treating and ageing to final strength.
Values for the O condition
Other 2A90 tempers and conditions
2A90 is listed in 3 conditions; see the grade overview at 2A90.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OThis page Annealed | Use the annealed state for forging blanks or wherever maximum plasticity (18% elongation, 60 HB) is required before re-solution treating and ageing to final strength. | 90 | 180 | 18 | 60 HB | 45 % IACS |
Solution heat treated and naturally aged | Choose solution heat treated and naturally aged stock as the intermediate state when parts must still be formed or straightened after quenching and are artificially aged afterwards. | 200 | 340 | 15 | 95 HB | 32 % IACS |
T6Default Solution heat treated and artificially aged | Specify solution heat treated and artificially aged for finished parts needing the best strength and thermal stability at room temperature and 150–250 °C; elongation falls to 10%. | 300 | 410 | 10 | 120 HB | 37 % IACS |
What is 2A90-O?
2A90-O is 2A90 in the O temper — use the annealed state for forging blanks or wherever maximum plasticity (18% elongation, 60 HB) is required before re-solution treating and ageing to final strength. 2A90-O has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 180 MPa (26.1 ksi) — weaker than 87% of aluminum grades. Elongation at break is 18% and the elastic modulus is 74 GPa (10.7 Msi). 2A90-O 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). T6 is the default condition FabDigit quotes; O is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 18%, better than 86% of aluminum grades
- High electrical conductivity — 45 % IACS, better than 86% of aluminum grades
- Forms and bends easily — 60/100, better than 77% of aluminum grades
- Conducts heat well — 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades
Limitations
- Needs corrosion protection — 33/100, worse than 91% of aluminum grades
- Low strength — 90 MPa (13.1 ksi), worse than 87% of aluminum grades
- Difficult to weld — 22/100, worse than 83% of aluminum grades
2A90-O properties
Typical room-temperature values for 2A90-O; 11 are specific to this condition. Other listed values are 2A90 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2A90-O 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).
Mechanical15
2A90-O has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 180 MPa (26.1 ksi) — weaker than 87% of aluminum grades. Elongation at break is 18% and the elastic modulus is 74 GPa (10.7 Msi).
Thermal6
2A90-O is rated for continuous service to 150°C (302 °F). It conducts heat at 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades. Thermal expansion is 21.8 µm/m·K (12.1 µin/in·°F).
Electrical3
2A90-O conducts electricity at 45 % IACS, better than 86% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (33/100), worse than 91% of aluminum grades.
Sustainability4
Producing a kilogram of 2A90-O takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 15%.
Manufacturability7
2A90-O's machinability is fair (45/100, worse than 72% of aluminum grades); weldability poor (22/100); formability good (60/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2A90-O
Is 2A90 easy to machine?
Cutting in T6 is good with clean chip breaking, but the Al-Cu-Ni hard phases wear tooling. Use PCD or diamond-coated tools, high spindle speeds and plenty of emulsion coolant.
Can 2A90 be welded?
TIG and MIG welding show a strong hot-cracking tendency and soften the joint, so the alloy is generally not fusion welded. Use bolting, riveting, or friction and resistance welding, with re-solution treatment and ageing afterwards where required.
Can 2A90 be formed, bent or molded?
Suited to hot forging and hot extrusion at 380–460 °C; the temperature range is narrow and needs tight control. Cold bending and cold heading in T6 are poor, so cold form in O or T4.
What surface finishes work on 2A90?
Sulfuric or hard anodizing gives a dark grey film; for cosmetic parts use conversion coating plus primer and paint. In marine environments the high-copper base needs full coating or alclad protection.
2A90 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 | 0.5 – 1 | 0.75 |
| Feforms heat-resistant phase with Ni | 0.5 – 1 | 0.75 |
| Cu | 3.5 – 4.5 | 4 |
| Mnimpurity limit | ≤ 0.2 | — |
| Mg | 0.4 – 0.8 | 0.6 |
| Nimain heat-resistance strengthening element | 1.8 – 2.3 | 2 |
| Znimpurity limit | ≤ 0.3 | — |
| Tigrain refiner | ≤ 0.15 | — |
| Others (each)individual other element | ≤ 0.05 | — |
| Others (total)total of other elements | ≤ 0.15 | — |
| Al | balance | — |
2A90-O — frequently asked
What is 2A90-O used for?
2A90-O is typically used for engine forgings, high-temperature structural parts, hot-extruded sections for engine hardware, machined turbine-adjacent fittings, forged brackets near hot sections and compressor and accessory components. In short: heat-resistant 2000-series forging alloy; strength near 200 °C; narrow forging window.
What is the yield strength of 2A90-O?
2A90-O has a typical yield strength of 90 MPa (13.1 ksi) and a tensile strength of 180 MPa (26.1 ksi) — weaker than 87% of aluminum grades. Strength varies by condition: see the 3 listed tempers.
Is 2A90-O easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 72% of aluminum grades). Cutting in T6 is good with clean chip breaking, but the Al-Cu-Ni hard phases wear tooling. Use PCD or diamond-coated tools, high spindle speeds and plenty of emulsion coolant.
Can 2A90-O be welded?
Not readily — weldability is rated poor (22/100). TIG and MIG welding show a strong hot-cracking tendency and soften the joint, so the alloy is generally not fusion welded. Use bolting, riveting, or friction and resistance welding, with re-solution treatment and ageing afterwards where required.
What surface finishes work on 2A90-O?
Sulfuric or hard anodizing gives a dark grey film; for cosmetic parts use conversion coating plus primer and paint. In marine environments the high-copper base needs full coating or alclad protection.
Can 2A90-O be formed, bent or molded?
Suited to hot forging and hot extrusion at 380–460 °C; the temperature range is narrow and needs tight control. Cold bending and cold heading in T6 are poor, so cold form in O or T4.
What is the maximum service temperature of 2A90-O?
2A90-O 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 2A90-T6 and 2A90-O?
T6 is the default condition — specify solution heat treated and artificially aged for finished parts needing the best strength and thermal stability at room temperature and 150–250 °C; elongation falls to 10%. O: use the annealed state for forging blanks or wherever maximum plasticity (18% elongation, 60 HB) is required before re-solution treating and ageing to final strength. Yield strength is 300 MPa in T6 versus 90 MPa in O.
Sources
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys — ASM International (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.