Aluminum 2A70-T6
Temper · default condition
GB 2A70
T6 = solution heat treated and artificially aged
Standard supply condition for pistons, impellers and hot-running forgings — peak strength plus stable elevated-temperature properties.
Values for the T6 condition
Other 2A70 tempers and conditions
2A70 is listed in 5 conditions; see the grade overview at 2A70.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for deep forming, straightening or intermediate machining before heat treatment. | 120 | 230 | 18 | 65 HB | 48 % IACS |
As fabricated | Raw hot-worked forging or extrusion before solution treatment; used only as a semi-finished supply state. | 160 | 280 | 15 | 80 HB | 42 % IACS |
Solution heat treated and naturally aged | Intermediate state for parts that must be formed or straightened after quenching and then artificially aged. | 205 | 350 | 18 | 95 HB | 33 % IACS |
T6, stress relieved by compression | Choose for large forgings that must be heavily machined — residual stress is removed so parts stay dimensionally stable. | 345 | 420 | 9 | 118 HB | 38 % IACS |
T6DefaultThis page Solution heat treated and artificially aged | Standard supply condition for pistons, impellers and hot-running forgings — peak strength plus stable elevated-temperature properties. | 350 | 430 | 10 | 120 HB | 38 % IACS |
What is 2A70-T6?
2A70-T6 is 2A70 in the T6 temper — standard supply condition for pistons, impellers and hot-running forgings — peak strength plus stable elevated-temperature properties. 2A70-T6 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 83% of aluminum grades. Elongation at break is 10% and the elastic modulus is 73 GPa (10.6 Msi). 2A70-T6 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 505°C (941 °F).
Advantages
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
- High strength — 350 MPa (50.8 ksi), better than 83% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Needs corrosion protection — 32/100, worse than 94% of aluminum grades
- Difficult to weld — 22/100, worse than 83% of aluminum grades
2A70-T6 properties
Typical room-temperature values for 2A70-T6; 13 are specific to this condition. Other listed values are 2A70 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2A70-T6 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 505°C (941 °F).
Mechanical15
2A70-T6 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 83% of aluminum grades. Elongation at break is 10% and the elastic modulus is 73 GPa (10.6 Msi).
Thermal6
2A70-T6 is rated for continuous service to 200°C (392 °F). It conducts heat at 145 W/m·K (83.8 BTU/hr·ft·°F), better than 53% of aluminum grades. Thermal expansion is 22.3 µm/m·K (12.4 µin/in·°F).
Electrical3
2A70-T6 conducts electricity at 38 % IACS, better than 61% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 94% of aluminum grades.
Sustainability4
Producing a kilogram of 2A70-T6 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 10%.
Manufacturability8
2A70-T6's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (22/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2A70-T6
Is 2A70 easy to machine?
Machines well in T6 with sharp carbide tools and flood coolant, but the hard Al9FeNi/Al7Cu2Fe particles are abrasive — expect faster tool wear than 6061 and use PCD for high-volume piston turning.
Can 2A70 be welded?
Fusion welding is not recommended (hot-cracking, loss of aged strength); join by bolting, riveting, shrink fit or friction/inertia welding with post-weld re-ageing.
Can 2A70 be formed, bent or molded?
Designed for hot die forging and extrusion at roughly 380–460 °C; cold forming in T6 is very limited, form in O or T4 and age afterwards.
What surface finishes work on 2A70?
Use hard or chromic anodizing, chemical conversion coating or Ni/Sn plating for pistons; decorative sulfuric anodizing gives dark uneven color due to Cu-Ni phases.
2A70 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 | 1.9 – 2.5 | 2.2 |
| Mg | 1.4 – 1.8 | 1.6 |
| Fedeliberate addition, forms Al9FeNi | 0.9 – 1.5 | 1.2 |
| Niheat-resistance phase former | 0.9 – 1.5 | 1.2 |
| Tigrain refiner | 0.02 – 0.1 | 0.05 |
| Si | ≤ 0.35 | — |
| Mn | ≤ 0.2 | — |
| Zn | ≤ 0.3 | — |
| Others (each)total ≤ 0.15 | ≤ 0.05 | — |
| Al | balance | — |
2A70-T6 — frequently asked
What is 2A70-T6 used for?
2A70-T6 is typically used for forged engine pistons, high-temperature forged structural parts, engine accessory brackets and links, extruded sections for elevated-temperature service, hot-section machined fittings and compressor and engine housings. In short: service to 200 °C; 2618-class piston alloy; abrasive Fe-Ni phases.
What is the yield strength of 2A70-T6?
2A70-T6 has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 83% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is 2A70-T6 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well in T6 with sharp carbide tools and flood coolant, but the hard Al9FeNi/Al7Cu2Fe particles are abrasive — expect faster tool wear than 6061 and use PCD for high-volume piston turning.
Can 2A70-T6 be welded?
Not readily — weldability is rated poor (22/100). Fusion welding is not recommended (hot-cracking, loss of aged strength); join by bolting, riveting, shrink fit or friction/inertia welding with post-weld re-ageing.
What surface finishes work on 2A70-T6?
Use hard or chromic anodizing, chemical conversion coating or Ni/Sn plating for pistons; decorative sulfuric anodizing gives dark uneven color due to Cu-Ni phases.
Can 2A70-T6 be formed, bent or molded?
Designed for hot die forging and extrusion at roughly 380–460 °C; cold forming in T6 is very limited, form in O or T4 and age afterwards.
What is the maximum service temperature of 2A70-T6?
2A70-T6 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 2A70-T6 and 2A70-O?
T6 is the default condition — standard supply condition for pistons, impellers and hot-running forgings — peak strength plus stable elevated-temperature properties. O: softest condition for deep forming, straightening or intermediate machining before heat treatment. Yield strength is 350 MPa in T6 versus 120 MPa in O.
Sources
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys (2618 data) — ASM International (1990)
- Aluminum Association Teal Sheets — alloy/temper designations — The Aluminum Association (2018)
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.