2618A Aluminum

Representative aluminum raw/semi-finished material photo; exact grade not verified

2618A Aluminum is a registered wrought Al–Cu–Mg–Ni alloy developed for forged and other high-performance products operating at elevated temperature. Compared with conventional high-strength 2xxx alloys, its nickel-bearing composition is valued for better retention of useful strength in hot engine-service environments. It is commonly specified as solution heat-treated and artificially aged material, including stress-relieved T851 forgings. Typical uses include aerospace engine hardware, highly loaded forgings and performance-engine pistons, where low mass, machinability and hot-strength capability are important.

Chemical Composition (wt.%)
Chemical Composition wt.%
Element	Min	Max
Silicon	0.15	0.25
Iron	0.9	1.4
Copper	1.8	2.7
Manganese	—	0.25
Magnesium	1.2	1.8
Nickel	0.8	1.4
Zinc	—	0.15
Titanium	—	0.20
Other elements, each	—	0.05
Other elements, total	—	0.15
Aluminum	Remainder

Composition notes

Silicon: Registered limit, mass %.
Iron: Registered limit, mass %.
Copper: Registered limit, mass %.
Magnesium: Registered limit, mass %.
Nickel: Registered limit, mass %.
Titanium: Combined zirconium plus titanium is limited to 0.25%.
Aluminum: Balance.

Registered composition limits for wrought 2618A, in mass percent. Manganese, zinc and titanium are maximum limits. The additional restriction is zirconium plus titanium ≤0.25%; this does not replace the individual titanium limit.

Values below are source-reported nominal or tabulated values for EN AW-2618A bar and stated tempers, except density, which is the Aluminum Association calculated nominal density for active wrought 2618A. Mechanical properties vary with product form, section size, direction and heat treatment; procurement specifications govern acceptance.

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Table of 2618A Aluminum Properties

Table of 2618A Aluminum Properties
Physical Properties	Metric
Density	2.77 g/cm³2.77 g/cm³
Mechanical Properties	Metric
Elastic Modulus (T6/T651)	72 GPa
Tensile Strength (T6/T651)	420 MPa
Yield Strength (T6/T651)	360 MPa
Elongation at Break (T6/T651)	7 %
Tensile Strength (T851)	440 MPa
Yield Strength (T851)	410 MPa
Elongation at Break (T851)	4.5 %
Thermal Properties	Metric
Melting Range	560–650 °C
Specific Heat Capacity (T851)	880 J/(kg·K)
Thermal Conductivity (T851)	150 W/(m·K)
Thermal Expansion (T851)	23 µm/(m·K)
Electrical Properties	Metric
Electrical Conductivity	39.2 % IACS

Test conditions & data notes

Density: Calculated nominal density for active wrought 2618A.
Elastic Modulus (T6/T651): EN AW-2618A bar table.
Tensile Strength (T6/T651): EN AW-2618A bar table.
Yield Strength (T6/T651): EN AW-2618A bar table.
Elongation at Break (T6/T651): EN AW-2618A bar table.
Tensile Strength (T851): EN AW-2618A bar table.
Yield Strength (T851): EN AW-2618A bar table.
Elongation at Break (T851): EN AW-2618A bar table.
Melting Range: EN AW-2618A bar table.
Specific Heat Capacity (T851): EN AW-2618A bar table.
Thermal Conductivity (T851): EN AW-2618A bar table.
Thermal Expansion (T851): EN AW-2618A bar table.
Electrical Conductivity: At 20 °C; EN AW-2618A bar table.

Material Conditions & Tempers

2618A is supplied in several heat-treated and forged-product conditions. Temper selection must be tied to the applicable product specification, dimensions and required stress-relief condition. T6 is a common artificially aged condition; T851 is particularly relevant where controlled stretching after solution treatment is used to reduce residual stress before artificial ageing.

Condition	Tensile Strength	Yield / Proof Strength	Notes
T6	420 MPa	360 MPa	Solution heat-treated and artificially aged condition reported for EN AW-2618A bar. Reported bar-table values; section size and product specification affect guaranteed minima.
T651	420 MPa	360 MPa	Artificially aged, stress-relieved condition grouped with T6 in the cited EN AW-2618A bar table. Verify the exact stress-relief practice and product form with the mill specification.
T851	440 MPa	410 MPa	Solution heat-treated, stress-relieved by controlled stretching and artificially aged. EN 2086 coverage cited for hand and die forgings up to 150 mm for highly loaded aerospace parts up to 300 °C. The stated tensile values are reported for bar; forging-property requirements are specification and section dependent.

Advantages & Limitations

Advantages	Limitations
Nickel-bearing Al–Cu–Mg chemistry supports useful strength retention for elevated-temperature service compared with many conventional wrought aluminum alloys. Heat treatability permits a strength-focused T6 condition or stress-relieved artificially aged conditions such as T851. Low density relative to ferrous materials helps reduce reciprocating and rotating mass in pistons and aerospace hardware. Well suited to forged shapes and machining of complex, highly loaded components. T851 processing can improve dimensional stability by reducing residual stress before finish machining.	Copper-rich 2xxx alloys do not have the general corrosion resistance of 5xxx or 6xxx aluminum; assess coating, cladding or controlled service exposure where corrosion is significant. Strength, ductility and dimensional stability are strongly dependent on product form, section thickness and heat treatment; generic bar data are not design allowables for forgings. Fusion welding can be difficult and may degrade the heat-treated condition adjacent to the weld; welding procedures require application-specific qualification. It is not a universal high-temperature alloy: sustained-temperature capability and allowable stresses must be verified against the governing aerospace or engine specification. Nickel, copper and iron additions can make finishing and anodized appearance less uniform than in decorative aluminum alloys.

Advantages

Limitations

Nickel-bearing Al–Cu–Mg chemistry supports useful strength retention for elevated-temperature service compared with many conventional wrought aluminum alloys.
Heat treatability permits a strength-focused T6 condition or stress-relieved artificially aged conditions such as T851.
Low density relative to ferrous materials helps reduce reciprocating and rotating mass in pistons and aerospace hardware.
Well suited to forged shapes and machining of complex, highly loaded components.
T851 processing can improve dimensional stability by reducing residual stress before finish machining.

Copper-rich 2xxx alloys do not have the general corrosion resistance of 5xxx or 6xxx aluminum; assess coating, cladding or controlled service exposure where corrosion is significant.
Strength, ductility and dimensional stability are strongly dependent on product form, section thickness and heat treatment; generic bar data are not design allowables for forgings.
Fusion welding can be difficult and may degrade the heat-treated condition adjacent to the weld; welding procedures require application-specific qualification.
It is not a universal high-temperature alloy: sustained-temperature capability and allowable stresses must be verified against the governing aerospace or engine specification.
Nickel, copper and iron additions can make finishing and anodized appearance less uniform than in decorative aluminum alloys.

Processing & Fabrication

Process	Description
Forging	2618A is principally used as a wrought forging alloy. Use a controlled forging route and qualified reheating practice to achieve the required grain flow and properties in highly loaded parts; forging-process limits should come from the applicable product specification.
Solution treatment and artificial ageing	T6-type material is produced by solution heat treatment followed by artificial ageing. The exact thermal cycle must be selected for the product form and governing specification rather than inferred from a generic alloy designation.
Stress relief and ageing	For T851, solution-treated material is stress relieved by a controlled amount of stretching and then artificially aged, with no further straightening after stretching. This condition is useful where machining distortion must be controlled.
Machining	Machine after the specified heat treatment when dimensional stability is important. Use rigid workholding, appropriate coolant and balanced stock removal, particularly for thin webs and asymmetric forged sections.
Joining and finishing	Avoid assuming as-welded properties equivalent to aged base metal. Where corrosion or appearance matters, define cleaning, conversion coating, paint or other protective finishing in the component process plan.

Applications

2618A is selected when a lightweight wrought aluminum component must carry substantial load while seeing engine-adjacent or otherwise elevated temperatures. Its most characteristic applications combine forged geometry, fatigue-conscious design and hot-strength requirements.

Aircraft engine and aerospace forgings: T851 2618A is identified for highly loaded hand and die forgings; the alloy combines low mass with elevated-temperature performance.
High-performance engine pistons: The alloy’s elevated-temperature strength retention and relatively low density are valuable in reciprocating components exposed to combustion heat.
Connecting rods and highly loaded engine hardware: Forged 2618A can provide a strong, machinable aluminum solution where weight reduction and thermal exposure are both design concerns.
Precision-machined aerospace structural parts: Stress-relieved T851 stock helps limit residual-stress distortion during machining of close-tolerance components.

Standards & Designations

Designation	Value	Description
Aluminum Association	2618A	Registered active wrought aluminum-alloy designation; composition limits are listed in the Aluminum Association Teal Sheets.
EN	EN AW-2618A / EN 573-3	European designation and composition-standard cross reference shown by the material datasheet source.
DIN EN	DIN EN 2086:2006-10, 2618A-T851	Listed for AL-P2618A-T851; the cited note covers hand and die forgings to 150 mm for highly loaded aerospace parts up to 300 °C.

Frequently Asked Questions

Is 2618A the same alloy as 2618?

No. They are separate registered wrought designations with different composition limits. For example, 2618A specifies manganese up to 0.25% and different silicon, iron, copper, magnesium, nickel and titanium limits from 2618. Purchase documents should state the exact designation and required temper.

Why is 2618A used for pistons and engine-related parts?

Its Al–Cu–Mg–Ni composition is designed to retain useful mechanical capability at higher temperatures than many general-purpose aluminum alloys. This, together with low density and suitability for forging and machining, makes it useful for lightweight engine components. Actual temperature and fatigue allowables must be established from the applicable product specification.

What does T851 mean for 2618A?

T851 denotes solution heat treatment, stress relief by controlled stretching, and artificial ageing, with no further straightening after stretching. The stress-relief step is especially useful for precision-machined parts because it helps reduce residual-stress-related movement.

References & Data Notes

(n.d.). Aluminum Association — International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys, December 2025. https://www.aluminum.org/sites/default/files/2026-01/Teal%20Sheets%20December%202025.pdf
(n.d.). Applus+ Materials Portal — AL-P2618A-T851 | EN AW-2618A Material Datasheet. https://www.appluslaboratories.com/materials-portal/datasheet/al-p2618a-t851-en-aw-2618a/-1610067234
(n.d.). Mastar Metal — EN AW-2618A (DTD 5014A) Aluminum Bar. https://www.mastar-metal.com/bar/2618-bar

Chemical composition and nominal density are taken from the Aluminum Association registered wrought-alloy publication. Other numerical property values are source-reported EN AW-2618A bar values and should be treated as informative unless the applicable product specification, form, size and temper match the intended purchase.