Aluminum 2018
AA 2018 · UNS A92018
2018 (A92018) is an Al-Cu-Ni forging alloy developed for elevated-temperature strength retention, historically used in piston and engine applications.
Reference datasheet — 2018 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 T61 condition
2018 tempers and conditions
2018 is supplied in 4 conditions, soft to hard. T61 is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, used as intermediate stock for further forging, machining or straightening before heat treatment. | 70 | 140 | 20 | 45 HB | 46 % IACS |
As fabricated | As-forged stock with no controlled thermal treatment; properties vary with section and are not guaranteed, used only as pre-machining blank. | 140 | 250 | 15 | 70 HB | 44 % IACS |
Solution heat treated and naturally aged | Intermediate condition after solution treatment; moderate strength with more ductility, normally aged on to T61 for service. | 205 | 350 | 18 | 95 HB | 33 % IACS |
T61Default T6 variant, underaged | The standard supply condition for 2018 forgings; best combination of elevated-temperature strength and dimensional stability for pistons and engine parts. | 315 | 420 | 12 | 120 HB | 40 % IACS |
What is 2018?
2018 (A92018) is an Al-Cu-Ni forging alloy developed for elevated-temperature strength retention, historically used in piston and engine applications. It is chosen where parts must run hot: the default T61 condition gives 315 MPa yield, 420 MPa tensile, 12% elongation and 120 HB with a maximum service temperature of 200 °C, and stock is normally forging billet or forged shapes rather than plate. Limits are the usual Al-Cu ones — no practical fusion welding, poor cold formability, and corrosion protection required — plus restricted commercial availability. 2618/2618A is the modern replacement for the same duty. 2018 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 507°C (945 °F). 2018 has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 79% of aluminum grades. Elongation at break is 12% and the elastic modulus is 74 GPa (10.7 Msi).
What is 2018 used for?
- forged pistons
- cylinder heads
- aircraft engine parts
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 — 315 MPa (45.7 ksi), better than 79% of aluminum grades
Limitations
- Needs corrosion protection — 33/100, worse than 91% of aluminum grades
- Difficult to weld — 22/100, worse than 83% of aluminum grades
2018 properties
Typical room-temperature values for 2018-T61; bars are the position among aluminum grades.
Physical3
2018 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 507°C (945 °F).
Mechanical13
2018 has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 79% of aluminum grades. Elongation at break is 12% and the elastic modulus is 74 GPa (10.7 Msi).
Thermal6
2018 is rated for continuous service to 200°C (392 °F). It conducts heat at 154 W/m·K (89 BTU/hr·ft·°F), better than 68% of aluminum grades. Thermal expansion is 22.3 µm/m·K (12.4 µin/in·°F).
Electrical3
2018 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (33/100), worse than 91% of aluminum grades.
Sustainability4
Producing a kilogram of 2018 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 20%.
Manufacturability6
2018'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. 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. 2018 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 2018
Is 2018 easy to machine?
Machines well in T61 with carbide tooling, high speeds and light feeds; hard Ni/Fe intermetallics accelerate tool wear, so use flood coolant and sharp positive-rake geometry.
Can 2018 be welded?
Not recommended for fusion welding (severe hot cracking in Al-Cu); join by mechanical fasteners or, if unavoidable, resistance/friction-stir with post-weld solution treatment and re-aging.
Can 2018 be formed, bent or molded?
Primarily hot forged at ~400–450 °C; cold formability in T61 is poor — bend or straighten only in O or freshly solution-treated condition.
2018 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 |
|---|---|---|
| Cuprincipal strengthener (Al₂Cu) | 3.5 – 4.5 | 4 |
| Nithermally stable Al-Cu-Ni intermetallics | 1.7 – 2.3 | 2 |
| Mg | 0.45 – 0.9 | 0.7 |
| Siimpurity limit | ≤ 0.9 | |
| Feimpurity limit | ≤ 1 | |
| Mn | ≤ 0.2 | |
| Cr | ≤ 0.1 | |
| Zn | ≤ 0.25 | |
| Tigrain refiner | ≤ 0.15 | |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on 2018?
Hard anodize for wear surfaces (dark, non-uniform color); chromate conversion or primer + paint recommended for corrosion protection; avoid decorative clear anodize.
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 2018 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A92018
- Also called
- 2018-T61
How much does 2018 cost?
2018 is a premium-cost aluminum ($$$), cheaper than about 51% 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.
2018 — frequently asked
What is 2018 used for?
2018 is typically used for forged pistons, cylinder heads and aircraft engine parts. In short: hot-strength forging alloy; 200 °C service capability; legacy piston-alloy grade.
What is the yield strength of 2018?
2018 has a typical yield strength of 315 MPa (45.7 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 79% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 2018 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well in T61 with carbide tooling, high speeds and light feeds; hard Ni/Fe intermetallics accelerate tool wear, so use flood coolant and sharp positive-rake geometry.
Can 2018 be welded?
Not readily — weldability is rated poor (22/100). Not recommended for fusion welding (severe hot cracking in Al-Cu); join by mechanical fasteners or, if unavoidable, resistance/friction-stir with post-weld solution treatment and re-aging.
What surface finishes work on 2018?
Hard anodize for wear surfaces (dark, non-uniform color); chromate conversion or primer + paint recommended for corrosion protection; avoid decorative clear anodize.
Can 2018 be formed, bent or molded?
Primarily hot forged at ~400–450 °C; cold formability in T61 is poor — bend or straighten only in O or freshly solution-treated condition.
What is the maximum service temperature of 2018?
2018 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 2018-T61 and 2018-O?
T61 is the default condition — the standard supply condition for 2018 forgings; best combination of elevated-temperature strength and dimensional stability for pistons and engine parts. O: softest condition, used as intermediate stock for further forging, machining or straightening before heat treatment. Yield strength is 315 MPa in T61 versus 70 MPa in O.
How much does 2018 cost?
2018 is a premium-cost aluminum ($$$), cheaper than about 51% 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: Properties and Physical Metallurgy (ed. J.E. Hatch) — ASM International (1984)
- ASTM B247 — Aluminum-Alloy Die, Hand and Rolled Ring Forgings — ASTM International (2020)
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.