T61 forged plate and blocks
Solution treated, quenched in boiling water to limit residual stress, and artificially aged. The standard condition for forgings and forged plate for pistons and wheels.
Heat-resistant Al-Cu-Mg-Ni plate
2618 / 2618A Aluminium Plate & Forged Plate
2618 and 2618A are aluminium-copper-magnesium alloys with nickel and iron additions that keep their strength at temperatures where most aluminium alloys soften, roughly 150 – 250 °C. Metline supplies 2618A rolled plate in T651 and T851, forged plate and blocks in T61, and clad sheet, certified to the specification on your drawing, to customers worldwide.
- Alloy
- Al-Cu-Mg-Ni-Fe
- Tempers
- T61, T6, T651, T851
- Service temperature
- up to about 200 – 250 °C
- Forms
- Plate, forged plate, clad sheet
What is 2618 aluminium?
2618 was developed in Britain as Hiduminium RR58 for aero-engine parts and later became the skin alloy of the Concorde supersonic airliner, whose surface heated to over 100 °C in cruise. Nickel and iron form thermally stable Al9FeNi particles that resist coarsening, so the alloy holds strength and creep resistance far better than 2024 or 7075 at elevated temperature.
Today 2618 is the classic material for forged pistons, turbocharger and compressor wheels, impellers and other rotating or hot-running components, as well as aircraft and engine structure that operates warm. Rolled and forged plate is used to machine prototype and low-volume parts that would otherwise be forged to shape, such as compressor wheels for motorsport and test engines.
Two versions exist. 2618 is the Aluminum Association grade used with AMS specifications (for example AMS 4132 for T61 die and hand forgings). 2618A is the European grade (EN AW-2618A, AlCu2Mg1.5Ni) with slightly wider limits, used for plate and clad sheet under EN and UK aerospace standards.
2618 and 2618A chemical composition (wt %)
| Element | 2618 (AA) | 2618A (EN 573-3) |
|---|---|---|
| Silicon (Si) | 0.10 – 0.25 | 0.15 – 0.25 |
| Iron (Fe) | 0.9 – 1.3 | 0.9 – 1.4 |
| Copper (Cu) | 1.9 – 2.7 | 1.8 – 2.7 |
| Manganese (Mn) | — | ≤ 0.25 |
| Magnesium (Mg) | 1.3 – 1.8 | 1.2 – 1.8 |
| Nickel (Ni) | 0.9 – 1.2 | 0.8 – 1.4 |
| Zinc (Zn) | ≤ 0.10 | ≤ 0.15 |
| Titanium (Ti) | 0.04 – 0.10 | ≤ 0.20 (Ti + Zr ≤ 0.25) |
| Others, each / total | 0.05 / 0.15 | 0.05 / 0.15 |
| Aluminium (Al) | Remainder | Remainder |
Iron and nickel are deliberate alloying elements here, not impurities. The mill certificate reports the analysis for each lot.
Mechanical and physical properties
Room-temperature typical values for the T61 temper are shown below. 2618 is not the strongest aluminium alloy at room temperature; its value lies in how much of that strength it keeps after long exposure at 150 – 250 °C, where 2024 and 7075 lose strength quickly. For hot design, use elevated-temperature and creep data from handbooks such as MMPDS or ASM.
| Condition | Tensile strength | Yield strength | Elongation | Hardness |
|---|---|---|---|---|
| 2618-T61 (typical) | about 420 – 440 MPa | about 350 – 370 MPa | 6 – 10 % | about 115 HB |
| 2618A-T651 / T851 plate (typical) | about 410 – 440 MPa | about 360 – 380 MPa | 5 – 8 % | — |
Physical properties (T61, typical)
- Density
- 2.76 g/cm³
- Modulus of elasticity
- about 74 GPa
- Thermal conductivity
- about 146 – 150 W/m·K
- Electrical conductivity
- about 37 % IACS
- Coefficient of thermal expansion
- about 22.3 µm/m·°C (20 – 100 °C)
- Melting range
- about 549 – 638 °C
2618 tempers and product forms
T651 rolled plate
Solution treated, stretched and aged. Flat, low-stress plate for machining.
T851 rolled plate
Stretched before artificial ageing; used under EN aerospace standards for structural plate.
T6 / T62 clad sheet
Thin sheet clad for corrosion protection, historically used for supersonic airframe skins (UK DTD 5070 family).
2618 standards and equivalent designations
| System | Designation | Typical specifications |
|---|---|---|
| Aluminum Association / SAE | 2618-T61 | AMS 4132 (die and hand forgings, rolled rings) |
| UNS | A92618 | — |
| European (EN) | EN AW-2618A / AlCu2Mg1.5Ni | EN 573-3; EN aerospace plate standards |
| German Werkstoff | 3.1924 | DIN / LW aerospace sheets |
| United Kingdom | RR58 (Hiduminium), 2618A | DTD 5070 clad sheet, BS aerospace series |
| France (old) | AU2GN | — |
AMS 4132 is a forging specification. Rolled plate is certified to EN or customer specifications; tell us the exact specification and revision on your drawing.
2618 supply range and weights
Supply range
- Clad sheet
- About 0.5 – 6 mm
- Rolled plate
- About 6 – 150 mm, T651 or T851
- Forged plate and blocks
- Heavy sections in T61 for machining wheels, pistons and housings
- Cut pieces
- Saw-cut blanks and discs to your sizes
- Inspection
- Ultrasonic testing and hardness / conductivity checks on request
2618 weighs about 2.76 kg per m² per millimetre of thickness:
| Thickness (mm) | kg per m² | 1220 × 2440 mm (kg) | 1500 × 3000 mm (kg) |
|---|---|---|---|
| 6 | 16.6 | 49.3 | 74.5 |
| 8 | 22.1 | 65.7 | 99.4 |
| 10 | 27.6 | 82.2 | 124.2 |
| 12 | 33.1 | 98.6 | 149.0 |
| 16 | 44.2 | 131.5 | 198.7 |
| 20 | 55.2 | 164.3 | 248.4 |
| 25 | 69.0 | 205.4 | 310.5 |
| 30 | 82.8 | 246.5 | 372.6 |
| 40 | 110.4 | 328.6 | 496.8 |
| 50 | 138.0 | 410.8 | 621.0 |
| 60 | 165.6 | 493.0 | 745.2 |
| 80 | 220.8 | 657.3 | 993.6 |
| 100 | 276.0 | 821.6 | 1242.0 |
| 150 | 414.0 | 1232.4 | 1863.0 |
| 200 | 552.0 | 1643.2 | 2484.0 |
Machining and processing 2618
Machining
Machines well in T61 with carbide tooling; iron-nickel particles are slightly abrasive, so expect somewhat shorter tool life than with 2024.
Welding
Not recommended for fusion welding; parts are machined from solid or forged to shape.
Corrosion
Moderate. Protect by anodising or coatings, or use clad sheet for skins.
Heat treatment
The boiling-water quench in T61 reduces residual stress in heavy sections. If re-heat-treating, follow the specification cycle closely.
Applications of 2618 plate and forgings
- Forged and machined pistons for high-performance and racing engines
- Turbocharger compressor wheels, impellers and fan components
- Aero-engine casings, rings and components running warm
- Supersonic and high-speed aircraft skins and structure
- Prototype and low-volume rotating parts machined from forged plate
For room-temperature structural use, 2024 or 7075 is stronger and cheaper. Choose 2618 when the part runs hot for long periods, and compare with 2219 when welding is also required.
How to order 2618 plate
- SpecifyAlloy (2618 or 2618A), form (rolled plate, forged plate, clad sheet), temper, size or drawing, quantity, specification and revision, and any ultrasonic class.
- QuoteWe confirm availability, tolerances, certification, packing and delivery terms (EXW, FOB, CIF or DAP) for your destination.
- ProcessMaterial is saw-cut to size, inspected and marked with alloy, temper and lot.
- DocumentEach delivery carries a mill test certificate to EN 10204 3.1 with the cast analysis and mechanical results for the lot; third-party inspection can be arranged on request.
- ShipSheets are interleaved or film-protected, packed on pallets or in seaworthy wooden cases, and shipped by sea or air to your port or door.
References and standards
- SAE AMS 4132 – Aluminum Alloy Die and Hand Forgings, Rolled Rings and Forging Stock (2618-T61)
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets)
- ASM Handbook, Volume 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
- MMPDS – Metallic Materials Properties Development and Standardization (successor to MIL-HDBK-5)
2618 aluminium (aluminum) plate: frequently asked questions
What is 2618 aluminium used for?
Parts that must stay strong at elevated temperature: forged pistons, turbocharger and compressor wheels, aero-engine parts and supersonic aircraft skins.
What is the difference between 2618 and 2618A?
2618 is the Aluminum Association grade used in AMS forging specifications; 2618A is the European grade with slightly wider composition limits. Properties are essentially the same.
Is 2618 better than 4032 for pistons?
4032 has lower thermal expansion and better wear resistance due to its high silicon; 2618 is tougher and more fatigue resistant, so it is preferred for highly loaded racing and boosted engines.
What does the T61 temper mean for 2618?
Solution heat-treated, quenched in boiling water to limit residual stress, then artificially aged. It is the standard temper for 2618 forgings.
Can 2618 be welded?
It is not normally fusion welded; parts are machined from solid or forged to shape.
Need 2618 plate or forged blocks?
Send form, temper, size, quantity and specification. We will reply with availability, certification and price.
