Aluminum 2618
AA 2618 · UNS A92618 · EN AW-2618, AW 2618 · GB 2A70, LD7
2618 is a heat-resistant Al-Cu-Mg alloy with deliberate Fe and Ni additions (the former British RR58/Hiduminium), in which Al9FeNi dispersoids keep strength and creep resistance usable at 150–230 °C.
2618 tempers and conditions
2618 is supplied in 6 conditions, soft to hard.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for deep forming, straightening or heavy machining before solution treating and ageing. | 125 | 215 | 18 | 65 HB | 41 % IACS |
Solution heat treated and artificially aged | General peak-aged condition for forgings and bar where no stress-relief stretching is applied. | 370 | 440 | 9 | 115 HB | 37 % IACS |
T6 variant, underaged | The standard supply condition for 2618 pistons, turbo wheels and elevated-temperature forgings — best balance of hot strength and residual-stress control. | 372 | 440 | 10 | 115 HB | 37 % IACS |
T6, stress relieved by stretching | Pick for plate and rolled bar that will be heavily machined — low residual stress means minimal distortion. | 375 | 440 | 9 | 118 HB | 37 % IACS |
T6, stress relieved by stretching, minor straightening | Extruded bar/profile equivalent of T651 — use for long machined parts needing straightness and low distortion. | 385 | 450 | 8 | 120 HB | 37 % IACS |
Solution treated, cold-worked by compression stress relief,… | Hand/die forgings where compressive stress relief raises strength slightly and cuts machining distortion. | 400 | 455 | 8 | 125 HB | 37 % IACS |
What is 2618?
2618 is a heat-resistant Al-Cu-Mg alloy with deliberate Fe and Ni additions (the former British RR58/Hiduminium), in which Al9FeNi dispersoids keep strength and creep resistance usable at 150–230 °C. It is supplied mainly as forgings, bar and extrusions for pistons, turbocharger impellers, aero-engine accessories and high-temperature structural parts, including supersonic aircraft skins. Corrosion resistance is poor and requires cladding, anodizing or coating; fusion weldability is poor, cold formability is limited, and cost is far above 6061/7075. 2218 is the nearest alternative. 2618 has a density of 2.76 g/cm³ (0.0997 lb/in³), heavier than 70% of aluminum grades. It melts at 549°C (1,020 °F). 2618 has a yield strength of 372 MPa (54 ksi) and a tensile strength of 440 MPa (63.8 ksi) — stronger than 85% of aluminum grades. Elongation at break is 10% and the elastic modulus is 74.5 GPa (10.8 Msi).
What is 2618 used for?
- Forged engine pistons
- Turbocharger compressor wheels
- Cylinder heads
- Aero-engine accessory components
- High-temperature structural forgings
- Supersonic aircraft skin panels
Advantages
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
- High strength — 372 MPa (54 ksi), better than 85% 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
2618 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
2618 has a density of 2.76 g/cm³ (0.0997 lb/in³), heavier than 70% of aluminum grades. It melts at 549°C (1,020 °F).
Mechanical15
2618 has a yield strength of 372 MPa (54 ksi) and a tensile strength of 440 MPa (63.8 ksi) — stronger than 85% of aluminum grades. Elongation at break is 10% and the elastic modulus is 74.5 GPa (10.8 Msi).
Thermal6
2618 is rated for continuous service to 200°C (392 °F). It conducts heat at 146 W/m·K (84.4 BTU/hr·ft·°F), better than 55% of aluminum grades. Thermal expansion is 22.3 µm/m·K (12.4 µin/in·°F).
Electrical3
2618 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 94% of aluminum grades.
Sustainability4
Producing a kilogram of 2618 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 5%.
Manufacturability8
2618's machinability is good (65/100, better than 62% 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. 2618 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 2618
Is 2618 easy to machine?
Machines cleanly in T6/T61 with sharp PCD or polished carbide, high speed and flood coolant; hard Fe-Ni intermetallics accelerate edge wear compared with 6061.
Can 2618 be welded?
Not recommended for fusion welding (hot cracking, loss of aged strength); join by mechanical fasteners, friction welding or FSW with post-weld ageing where qualified.
Can 2618 be formed, bent or molded?
Hot forge/extrude at 400–450 °C; cold forming only in O temper — T61 material is essentially non-formable and must be machined to shape.
Manufacturability
The process limits FabDigit applies to 2618. Every 2618 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Good65 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair25 / 100 |
|---|---|
| Weldability | Poor22 / 100 |
2618 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 | 0.1 – 0.25 | 0.18 |
| Feforms Al9FeNi dispersoids for creep strength | 0.9 – 1.3 | 1.1 |
| Cu | 1.9 – 2.7 | 2.3 |
| Mg | 1.3 – 1.8 | 1.5 |
| Ni | 0.9 – 1.2 | 1.05 |
| Ti | 0.04 – 0.1 | 0.07 |
| Zn | ≤ 0.1 | |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on 2618?
Hard anodize (Type III) for piston crowns and wear faces gives a dark grey, non-uniform film; chromate/TCP conversion coat plus primer for corrosion protection, and avoid bare seawater exposure.
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).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 2618 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A92618
- Aluminum Association
- AA2618
- EN / DIN / Werkstoff-Nr.
- AW-2618AW 26183.1924
- GB (China)
- 2A70LD7
- Also called
- 2618-T61
How much does 2618 cost?
2618 is a premium-cost aluminum ($$$), pricier than about 57% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
2618 — frequently asked
What is 2618 used for?
2618 is typically used for forged engine pistons, turbocharger compressor wheels, cylinder heads, aero-engine accessory components, high-temperature structural forgings and supersonic aircraft skin panels. In short: concorde alloy; high-temp aerospace.
What is the yield strength of 2618?
2618 has a typical yield strength of 372 MPa (54 ksi) and a tensile strength of 440 MPa (63.8 ksi) — stronger than 85% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 2618 easy to machine?
Reasonably — machinability is rated good (65/100, better than 62% of aluminum grades). Machines cleanly in T6/T61 with sharp PCD or polished carbide, high speed and flood coolant; hard Fe-Ni intermetallics accelerate edge wear compared with 6061.
Can 2618 be welded?
Not readily — weldability is rated poor (22/100). Not recommended for fusion welding (hot cracking, loss of aged strength); join by mechanical fasteners, friction welding or FSW with post-weld ageing where qualified.
What surface finishes work on 2618?
Hard anodize (Type III) for piston crowns and wear faces gives a dark grey, non-uniform film; chromate/TCP conversion coat plus primer for corrosion protection, and avoid bare seawater exposure.
Can 2618 be formed, bent or molded?
Hot forge/extrude at 400–450 °C; cold forming only in O temper — T61 material is essentially non-formable and must be machined to shape.
What is the maximum service temperature of 2618?
2618 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 2618 cost?
2618 is a premium-cost aluminum ($$$), pricier than about 57% 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.
Can FabDigit make parts in 2618?
Yes — 2618 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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)
- MMPDS (Metallic Materials Properties Development and Standardization) — FAA/Battelle (2023)
- AMS 4132 — Aluminum Alloy Forgings 2618, Solution and Precipitation Heat Treated — SAE International (2019)
- EN 573-3 / EN 586 — Aluminium and aluminium alloys, chemical composition and forgings — CEN (2019)
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.