Forming
T3 foil bends readily around moderate radii. For tight shapes, form in the O or freshly quenched (W) condition and then age; parts left too long in W harden naturally and lose formability within hours.
Aerospace thin-gauge material
2024 Aerospace Aluminium Foil and Thin Sheet
2024 aerospace foil is thin-gauge 2024 aluminium, typically 0.1 to 0.5 mm, rolled from the classic high-strength Al-Cu-Mg airframe alloy and usually supplied in the T3 or O temper. It is used where a very thin layer must still carry real load: fibre-metal laminates, shims, doublers, bonded skins and fatigue test specimens. Metline supplies bare and Alclad 2024 foil and strip worldwide, cut to size and certified to the specification on your order.
- Alloy
- 2024 (Al-Cu-Mg)
- Tempers
- O, T3, T42, T81
- Gauge
- About 0.1 – 0.5 mm
- Standards
- ASTM B209 · AMS 4037 · EN 485
What is 2024 aerospace foil?
In aerospace purchasing, "2024 foil" rarely means kitchen-style foil below 0.2 mm. It usually refers to very thin 2024 sheet and strip, from about 0.1 mm up to roughly 0.5 mm, rolled to the same chemistry and heat-treatment rules as heavier 2024 aircraft sheet.
2024 contains around 4.4 % copper and 1.5 % magnesium. After solution heat treatment and natural ageing it reaches a tensile strength close to 480 MPa, which is roughly three times that of the 1xxx and 8xxx alloys used for packaging foil. That strength, combined with excellent fatigue crack growth resistance, is why 2024-T3 remains the standard fatigue-critical skin alloy decades after it was introduced.
At foil gauges, the alloy behaves differently from plate. Thin material cools almost instantly when quenched, so properties are uniform through the thickness, but it is also more sensitive to surface damage, handling kinks and corrosion, because a small pit consumes a larger share of the section. Most buyers therefore choose Alclad 2024 or specify careful surface protection and packing.
2024 chemical composition (wt %)
Limits are the registered Aluminum Association values for 2024, which ASTM B209, the AMS sheet specifications and EN 573-3 (EN AW-2024, AlCu4Mg1) all follow. Alclad product adds a thin cladding layer, normally 1230 or a similar high-purity alloy, on each face.
| Element | Minimum | Maximum | Effect |
|---|---|---|---|
| Silicon (Si) | — | 0.50 | Impurity; held low for toughness |
| Iron (Fe) | — | 0.50 | Impurity; forms coarse particles that reduce fatigue life |
| Copper (Cu) | 3.8 | 4.9 | Main strengthening element (Al2CuMg precipitates) |
| Manganese (Mn) | 0.30 | 0.9 | Grain control and some strength |
| Magnesium (Mg) | 1.2 | 1.8 | Works with Cu to give a strong natural-ageing response |
| Chromium (Cr) | — | 0.10 | Impurity |
| Zinc (Zn) | — | 0.25 | Impurity |
| Titanium (Ti) | — | 0.15 | Grain refiner |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder | About 90.7 – 94.7 % |
Properties of 2024 foil by temper
Values below are typical figures for bare thin sheet. Specified minimums depend on thickness band, cladding and the governing standard; Alclad material is roughly 5 – 8 % weaker because the soft cladding carries little load. Always design to the minimums on the certificate, not to typical values.
| Temper | Tensile strength (typ.) | Yield strength (typ.) | Elongation (typ.) | Typical use |
|---|---|---|---|---|
| O (annealed) | 185 MPa | 75 MPa | 20 % | Forming, then heat treatment by the user |
| T3 | 483 MPa | 345 MPa | 18 % | Standard fatigue-critical skin and laminate temper |
| T42 | about 470 MPa | about 325 MPa | about 19 % | Heat treated by the user from O or F |
| T81 | 485 MPa | 450 MPa | 6 % | Higher yield, better elevated-temperature stability |
Typical values from ASM and Aluminum Association data. T351 and T851 are plate tempers (stretched plate over about 6 mm) and do not normally apply to foil gauges; if your drawing calls them up for thin material, ask us to confirm the intended temper.
Physical properties (T3)
- Density
- 2.78 g/cm³
- Modulus of elasticity
- 73 GPa
- Thermal conductivity
- About 121 W/m·K
- Electrical conductivity
- About 30 % IACS
- Coefficient of thermal expansion
- 23.2 µm/m·°C (20 – 100 °C)
- Melting range
- 502 – 638 °C
Specifications for 2024 thin sheet and foil
Thin 2024 material is ordered against the same documents as aircraft sheet. The specification decides temper, tolerance tables, cladding thickness and test frequency, so it should appear on every enquiry.
| Document | Scope |
|---|---|
| ASTM B209 / ASME SB-209 | General sheet and plate specification covering bare and Alclad 2024 in O, T3, T361, T4, T42, T81 and other tempers |
| AMS 4037 | 2024-T3 bare sheet and plate (aerospace) |
| AMS 4041 | Alclad 2024-T3 sheet and plate (aerospace) |
| AMS-QQ-A-250/4 and /5 | Former federal specifications for bare and Alclad 2024, still widely cited on drawings |
| EN 485 / EN 573-3 | European sheet and strip; EN AW-2024 composition |
| EN 4000-series (ASD-STAN) | European aerospace sheet standards, called up by some airframers |
Older drawings sometimes list a mixture of AMS and MIL numbers. Send the exact revision you need and we will confirm whether it can be certified as written.
Gauges, widths and processing
Typical supply range
- Thickness
- About 0.1 – 0.5 mm as foil and strip; heavier gauges as sheet
- Width
- Slit strip from narrow widths up to about 1250 mm
- Form
- Coil, slit coil, flat sheets or cut blanks
- Cladding
- Bare or Alclad (each face clad)
- Surface
- Mill finish, cleaned and degreased, paper interleaved or PVC film protected
- Processing
- Slitting, cut-to-length, shearing and blanking to drawing
Availability of very thin heat-treated gauges varies by mill run; tell us early if your project depends on a specific gauge.
Thickness tolerance matters more at foil gauges than anywhere else: a deviation of 0.01 mm is 4 % of a 0.25 mm sheet. For laminates and shims, state the tolerance you need rather than relying on the default standard tables.
Forming, bonding and protection
Adhesive bonding
Laminates and bonded doublers depend on surface preparation. Phosphoric-acid or chromic-acid anodising, or approved sol-gel treatments, are normally applied before priming and bonding.
Welding
2024 is not considered fusion-weldable for structure: it is prone to hot cracking and loses strength. Join foil by bonding, riveting or, in some cases, friction stir or resistance methods qualified by the user.
Corrosion protection
Bare 2024 must be anodised, conversion coated or primed. Alclad material carries its own sacrificial layer, which is why it dominates for external skins.
Handling
Thin gauges kink and scratch easily. Specify interleaving or film, avoid sliding sheets across each other, and store indoors away from condensation.
Cutting
Shear, slit or laser cut; avoid excessive heat input, which locally over-ages the alloy at the cut edge.
Where 2024 aerospace foil is used
- Fibre-metal laminates: thin 2024-T3 sheets alternated with glass-fibre layers give skins with very slow fatigue crack growth and good impact and fire resistance
- Shims and spacers: peel shims and solid shims in assemblies where the shim must match the strength of surrounding 2024 parts
- Repairs: bonded or riveted doublers and patches for 2024 skins
- Test programmes: fatigue and crack-growth coupons, adhesive lap-shear specimens
- Missiles and UAVs: thin load-carrying skins and internal webs
- Instruments: diaphragms and thin structural parts that need high strength and a stable modulus
For honeycomb cores, buyers should note that aerospace honeycomb is normally made from 5052, 5056 or 3003 foil rather than 2024; see our aircraft honeycomb guide.
2024 foil compared with other thin aerospace gauges
| Property | 2024-T3 | 7075-T6 | 5052-H38 | 1145-H19 |
|---|---|---|---|---|
| Typical tensile strength | 483 MPa | 572 MPa | 290 MPa | About 200 MPa |
| Fatigue crack growth resistance | Excellent | Fair | Good | Not structural |
| Corrosion resistance (bare) | Low | Low–fair | Very good | Excellent |
| Formability | Good | Poor | Good | Excellent |
| Typical use | Laminates, skins, shims | High-strength thin parts | Honeycomb, fuel-system parts | Capacitor, bonding, shielding foil |
Choose 2024-T3 when damage tolerance governs, 7075 when static strength is the priority and fatigue is less critical, and a 5xxx alloy when corrosion resistance or honeycomb fabrication matters more than strength.
How to order 2024 foil
- SpecifyAlloy and temper (for example Alclad 2024-T3), gauge and tolerance, width, coil or sheet form, quantity and the governing specification.
- Confirm the specificationWe check the order against the governing AMS, ASTM or EN document, confirm tempers, sizes, tolerances and any customer flow-down clauses, and quote on EXW, FOB, CIF or DAP terms.
- ProcessCoils are slit or cut to length, interleaved or film protected, and inspected for gauge, flatness and surface defects.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing heat or lot number, chemical analysis and mechanical test results, plus any ultrasonic or other inspection reports called for on the order.
- Pack and shipMaterial is protected against moisture and handling damage, packed in seaworthy cases or on pallets, marked for traceability and shipped by sea or air.
References and standards
- ASTM B209 – Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
- SAE AMS 4037 – Aluminum Alloy Sheet and Plate, 2024-T3
- EN 573-3 – Chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
- ASM Handbook Vol. 2 – Properties of Wrought Aluminum Alloys: 2024
2024 aerospace aluminium foil: frequently asked questions
Is 2024 available as true foil below 0.2 mm?
Very thin heat-treated 2024 is a specialist product made in limited mill runs. Gauges around 0.2 – 0.5 mm are more commonly available. Tell us your gauge and tolerance early so we can confirm feasibility.
Should I order bare or Alclad 2024 foil?
Alclad is the usual choice for parts exposed to the atmosphere, because the pure aluminium cladding protects the copper-bearing core. Bare material is chosen when the surface will be anodised and bonded, or when the slight strength loss from cladding is not acceptable.
Can 2024 aluminum foil be welded?
Not for structural joints. 2024 cracks during fusion welding and loses strength in the heat-affected zone. Use adhesive bonding, riveting or a joining method qualified for your part.
Why does my drawing call for T351 on thin material?
T351 is a stretched plate temper. Thin sheet and foil are normally supplied as T3 or T42. We will confirm the equivalent temper with you before ordering.
Do you supply mill certificates for aerospace foil?
Yes. Every lot carries an EN 10204 3.1 certificate with chemical analysis and mechanical results, traceable to the coil or sheet.
Need 2024 foil or thin sheet?
Send gauge, width, temper, cladding, quantity and specification. We will confirm what can be supplied and how it will be certified.
