Aluminum 2218 · temper · default condition
Aluminum 2218-T61
Properties of the T61 condition, compared with the other 2218 tempers.
Standard high-strength temper for 2218 pistons and engine forgings; mild quench limits distortion and residual stress.
What is 2218-T61?
2218-T61 is 2218 in the T61 temper — standard high-strength temper for 2218 pistons and engine forgings; mild quench limits distortion and residual stress. 2218-T61 has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 405 MPa (58.7 ksi) — stronger than 77% of aluminum grades. Elongation at break is 11% and the elastic modulus is 74 GPa (10.7 Msi). 2218-T61 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 505°C (941 °F).
Advantages
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
- High strength — 305 MPa (44.2 ksi), better than 77% of aluminum grades
Limitations
- Needs corrosion protection — 33/100, worse than 90% of aluminum grades
- Difficult to weld — 22/100, worse than 83% of aluminum grades
2218-T61 properties
Typical room-temperature values for 2218-T61 — 15 properties are specific to this condition; the rest are grade-level values shared by every 2218 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
2218-T61 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 505°C (941 °F).
Mechanical11
2218-T61 has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 405 MPa (58.7 ksi) — stronger than 77% of aluminum grades. Elongation at break is 11% and the elastic modulus is 74 GPa (10.7 Msi).
Thermal6
2218-T61 is rated for continuous service to 200°C (392 °F). It conducts heat at 147 W/m·K (84.9 BTU/hr·ft·°F), better than 55% of aluminum grades. Thermal expansion is 22.4 µm/m·K (12.4 µin/in·°F).
Electrical3
2218-T61 conducts electricity at 38 % IACS, better than 61% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (33/100), worse than 90% of aluminum grades.
Sustainability4
Producing a kilogram of 2218-T61 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 75% of aluminum grades. Typical recycled content is 20%.
Manufacturability6
2218-T61's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (22/100); formability poor (28/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 2218 tempers and conditions
2218 is also supplied in 3 other conditions. The full side-by-side table is on the 2218 overview.
- T61DefaultStandard high-strength temper for 2218 pistons and engine forgings; mild quench limits distortion and residual stress.305 MPa yield · 115 HB
- T6Generic peak-aged designation; for 2218 forgings it is supplied in practice as the T61 variant.305 MPa yield · 115 HB
- T71Intermediate overaged temper trading some strength for better dimensional stability at elevated temperature.275 MPa yield · 105 HB
- T72Choose for pistons and hot-running parts where growth-free dimensional stability above 200 °C matters more than peak strength.255 MPa yield · 95 HB
Working with 2218-T61
Is 2218 easy to machine?
Machines well in T61/T72 with sharp carbide tools and flood coolant, but Ni/Fe intermetallics are abrasive — expect faster edge wear than 6061; chips break cleanly at moderate feeds.
Can 2218 be welded?
Not recommended for fusion welding (hot-cracking of the Al-Cu-Ni system); join by mechanical fasteners or resistance/friction-stir methods with qualified procedures.
Can 2218 be formed, bent or molded?
A forging alloy — hot forge/upset around 400–455 °C; cold forming in aged tempers is very limited, form only in F or freshly solution-treated condition.
What surface finishes work on 2218?
Hard anodize or chromate/organic coating for corrosion and wear protection; decorative anodizing yields a dull grey-brown tone, and polishing reveals coarse intermetallic streaks.
2218 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 | ≤ 0.9 | 0.4 |
| Feforms Al-Fe-Ni intermetallics that give hot strength | ≤ 1 | 0.6 |
| Cu | 3.5 – 4.5 | 4 |
| Mn | ≤ 0.2 | 0.05 |
| Mg | 1.2 – 1.8 | 1.5 |
| Cr | ≤ 0.1 | — |
| Nikey elevated-temperature addition | 1.7 – 2.3 | 2 |
| Zn | ≤ 0.25 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
2218-T61 — frequently asked
What is 2218-T61 used for?
2218-T61 is typically used for forged engine pistons, cylinder heads, turbocharger impellers, jet-engine rings, high-temperature forged brackets and hot-end machined engine hardware. In short: engine pistons; heat-resistant.
What is the yield strength of 2218-T61?
2218-T61 has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 405 MPa (58.7 ksi) — stronger than 77% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 2218-T61 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well in T61/T72 with sharp carbide tools and flood coolant, but Ni/Fe intermetallics are abrasive — expect faster edge wear than 6061; chips break cleanly at moderate feeds.
Can 2218-T61 be welded?
Not readily — weldability is rated poor (22/100). Not recommended for fusion welding (hot-cracking of the Al-Cu-Ni system); join by mechanical fasteners or resistance/friction-stir methods with qualified procedures.
What surface finishes work on 2218-T61?
Hard anodize or chromate/organic coating for corrosion and wear protection; decorative anodizing yields a dull grey-brown tone, and polishing reveals coarse intermetallic streaks.
Can 2218-T61 be formed, bent or molded?
A forging alloy — hot forge/upset around 400–455 °C; cold forming in aged tempers is very limited, form only in F or freshly solution-treated condition.
What is the maximum service temperature of 2218-T61?
2218-T61 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 2218-T61 and 2218-T72?
T61 is the default condition — standard high-strength temper for 2218 pistons and engine forgings; mild quench limits distortion and residual stress. T72: choose for pistons and hot-running parts where growth-free dimensional stability above 200 °C matters more than peak strength. Yield strength is 305 MPa in T61 versus 255 MPa in T72.
Can FabDigit make parts in 2218-T61?
Yes — 2218-T61 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 Handbook Vol. 2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- Aluminum: Properties and Physical Metallurgy — ASM International (1984)
- EN 573-3 Aluminium and aluminium alloys — Chemical composition — CEN (2019)
- Aluminium alloy property tables (2xxx elevated-temperature forging alloys) — MatWeb / ASM Alloy Center (2023)
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.