1163T
Solution heat-treated, quenched and naturally aged; the standard condition for skin sheet. Comparable to the T3 / T351 tempers of 2024 and 2524.
GOST aerospace alloy
1163 / 1163T Aluminium Alloy (ГОСТ System)
1163 is a Russian high-purity aluminium-copper-magnesium alloy developed from Д16 (the GOST counterpart of 2024) for fatigue-critical aircraft skins. Lower iron and silicon give it better fracture toughness and slower fatigue crack growth than standard Д16 at similar strength. 1163T denotes sheet or plate in the quenched and naturally aged condition, the usual supply state.
- System
- Al-Cu-Mg (2xxx type)
- Main condition
- 1163T: quenched + naturally aged
- Closest analogues
- 2524-T3, 2024-T3 (higher purity)
- Forms
- Clad sheet, plate, extrusions
What is 1163 aluminium alloy?
In the four-digit Russian system, alloys numbered 116x are variants of Д16 (1160), the duralumin used for most Soviet and Russian airframe skins and stringers. 1163 is the damage-tolerant member of that family. Its copper, magnesium and manganese levels sit inside the Д16 range, but iron and silicon are held to a fraction of the Д16 limits.
Iron and silicon form coarse intermetallic particles that act as crack starters and speed up crack growth. Removing most of them does little to tensile strength but markedly improves fracture toughness, residual strength after damage and fatigue crack growth resistance. The same idea produced 2324 and 2524 in the Western system, which is why 1163T is usually compared with 2524-T3 and with high-purity 2024-T3 sheet.
The alloy is used mainly where a cracked panel must still carry load until it is found at inspection: pressurised fuselage skins, lower wing skins and other tension-dominated structure. For the buyer, this means 1163 is not an ordinary commercial alloy; it is supplied against aerospace specifications with full traceability.
1163 composition compared with Д16 and 2024
Exact limits for 1163 are set in the governing aerospace documents and differ slightly between sources, so the 1163 column shows nominal levels and the impurity caps commonly quoted for it. The Д16 and 2024 columns are the registered limits.
| Element (%) | 1163 (nominal) | Д16 / 1160 (GOST 4784) | 2024 (AA) |
|---|---|---|---|
| Copper (Cu) | about 3.8 – 4.5 | 3.8 – 4.9 | 3.8 – 4.9 |
| Magnesium (Mg) | about 1.2 – 1.6 | 1.2 – 1.8 | 1.2 – 1.8 |
| Manganese (Mn) | about 0.4 – 0.8 | 0.3 – 0.9 | 0.30 – 0.9 |
| Iron (Fe) | ≤ 0.15 | ≤ 0.5 | ≤ 0.50 |
| Silicon (Si) | ≤ 0.10 | ≤ 0.5 | ≤ 0.50 |
| Zinc (Zn) | low | ≤ 0.3 | ≤ 0.25 |
| Titanium (Ti) | small grain-refining addition | ≤ 0.15 | ≤ 0.15 |
| Aluminium | Remainder | Remainder | Remainder |
Always work to the composition in the order specification and the mill certificate. The figures above are for comparison, not for acceptance.
Mechanical properties: what to expect
1163T belongs to the same strength class as Д16Т and 2024-T3 sheet. For orientation, 2024-T3 sheet has typical properties of about 483 MPa tensile strength, 345 MPa yield strength and 18 % elongation, and specified minimums for clad sheet are lower, around 400 MPa tensile and 270 MPa yield depending on thickness. Clad 1163T sheet falls in a similar band. Its advantage is not higher strength but higher fracture toughness and residual strength.
| Property | 1163T (high-purity) | Д16Т / 2024-T3 (standard purity) |
|---|---|---|
| Tensile and yield strength | Similar class | Reference |
| Plane-stress fracture toughness | Higher | Reference |
| Fatigue crack growth rate | Slower, especially at medium stress intensity | Reference |
| Elastic modulus | About 72 GPa | About 72 GPa |
| Density | About 2.78 g/cm³ | 2.78 g/cm³ |
| Corrosion | Requires cladding or coatings | Requires cladding or coatings |
Some supplier pages quote 600–650 MPa tensile strength and very high toughness for 1163 plate. Those values belong to 7xxx alloys, not to an Al-Cu-Mg alloy in a naturally aged temper, and should not be used for design. Use the guaranteed values in the order specification.
1163 supply conditions
Clad sheet (А)
Thin layers of purer aluminium on both faces give sacrificial corrosion protection, as with Alclad 2024. Account for the cladding when calculating strength.
Thick plate
Plate for machined parts is stretched after quenching to relieve stress. Through-thickness properties are lower than longitudinal ones, so specify test directions.
Annealed (М)
Soft condition for forming, followed by heat treatment of the finished part.
Product forms, inspection and documents
Typical supply
- Sheet
- Clad sheet for fuselage and wing skins; thickness and size to drawing
- Plate
- Stretched plate for machined fittings and integral panels
- Extrusions
- Stringers and profiles in compatible high-purity Al-Cu-Mg alloys
- Testing
- Tensile in specified directions, cladding thickness, grain size, ultrasonic inspection of plate
- Documents
- Mill certificate with chemistry and mechanical results; programme-specific approvals as required
For aerospace orders, list the governing specification, approved sources, test directions, ultrasonic class and documentation in the enquiry. Where an approved Western alloy is acceptable, 2524-T3 or high-purity 2024-T3 sheet is usually easier to source and certify.
Forming, machining and joining
- Forming: stretch forming of skins is done in fresh-quenched or annealed condition, then the part is aged; heavy forming in 1163T is limited.
- Machining: machines like 2024: short chips, good finish with sharp carbide tools. Use stress-relieved plate for deep pockets.
- Joining: riveting and bolting. Like other 2xxx alloys, 1163 is not fusion-welded for structural joints because of hot cracking and loss of strength.
- Surface treatment: anodising (sulphuric or chromic-free processes) and primers protect machined surfaces where cladding has been removed.
Where 1163 is used
- Pressurised fuselage skins of airliners and transport aircraft
- Lower wing skins and other tension-dominated panels
- Fatigue-critical frames and doublers
- Replacement parts and repairs on aircraft designed to GOST/OST materials
Outside aerospace, there is rarely a reason to pay for the high purity of 1163; standard 2024 or 2017A gives the same static strength at lower cost.
References and standards
- GOST 4784-97 – Aluminium and wrought aluminium alloys. Grades
- ASTM B209 – Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
- ASM Handbook – 2524 tough, moderate-strength sheet and thin plate
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
1163 aluminium alloy: frequently asked questions
What does the T in 1163T mean?
Quenched after solution heat treatment and naturally aged at room temperature, equivalent in principle to the T3 / T4 family of tempers in the Western system.
What is the Western equivalent of 1163?
There is no exact equivalent, but 2524-T3 and high-purity 2024-T3 sheet are the closest in purpose and properties. Substitution on an aircraft requires approval from the design authority.
Is 1163 stronger than Д16?
Not significantly. Its strength is similar; the benefit is higher fracture toughness and slower fatigue crack growth because iron and silicon are much lower.
Can 1163 be welded?
Structural fusion welding is not used. Joints are riveted or bolted, as with Д16 and 2024.
Can Metline supply 1163?
We can review 1163 enquiries and approved alternatives. Send the specification and documentation requirements, and we will confirm what can be supplied with mill certificates.
Need damage-tolerant Al-Cu-Mg sheet?
Send the specification, temper, size and quantity for 1163 or an approved alternative. We will reply with availability and certification.
