What Is the Standard Aluminum for Aircraft?

In the aerospace industry, material selection is critical to the success, safety, and performance of every aircraft. Among all the metals used in aviation, aluminum remains one of the most important. Lightweight, strong, corrosion-resistant, and easy to fabricate, aluminum alloys are the backbone of aircraft structures — from the fuselage to the wings, landing gear, and fuel tanks.

But one question arises frequently: What is the standard aluminum for aircraft? The short answer is that several specific aluminum grades, particularly those in the 2000 and 7000 series, are considered aerospace standards because they combine high strength and low weight.

This article takes an in-depth look at the standard aluminum alloys used in aircraft manufacturing, explaining their compositions, properties, and key applications. As an international supplier of aerospace-grade materials, SASAALUMINUM provides expert insight into why these alloys remain the top choice for the world’s leading aircraft manufacturers.

1. Why Aluminum Is Used in Aircraft Construction

Aluminum is one of the most widely used metals in aviation because it offers the ideal balance between performance and efficiency. Modern aircraft rely heavily on aluminum alloys for their structural framework, covering, and interior fittings.

Key Advantages of Aluminum in Aerospace:

• Low density: Aluminum weighs about one-third as much as steel, helping reduce aircraft weight and fuel consumption.

• High strength-to-weight ratio: Provides durability and load-bearing capability without adding mass.

• Excellent corrosion resistance: Forms a natural oxide layer that protects against environmental damage.

• Ease of fabrication: Aluminum can be machined, extruded, rolled, and welded into complex shapes.

• Cost-effective and recyclable: Aluminum is less expensive than titanium or composites and can be recycled indefinitely without losing performance.

These attributes make aluminum the foundation of both commercial and military aircraft structures.

2. What Does “Standard Aluminum for Aircraft” Mean?

When engineers refer to “standard aluminum for aircraft,” they are talking about aluminum alloys that meet aerospace-grade specifications such as ASTM, AMS (Aerospace Material Specification), or EN standards. These alloys are engineered for superior strength, fatigue resistance, and reliability under extreme temperature and stress conditions.

The most common standard aluminum grades used in aviation include:

• 2024 Aluminum Alloy

• 6061 Aluminum Alloy

• 7050 Aluminum Alloy

• 7075 Aluminum Alloy

These alloys are specifically designed to meet the demanding performance requirements of aircraft manufacturing, from fuselage frames to engine components.

3. The 2000 Series – Aluminum-Copper Alloys (High Strength for Aircraft Structures)

The 2000 series aluminum alloys are among the oldest and most widely used in aircraft applications. Their main alloying element is copper, which provides high strength and fatigue resistance.

Example: 2024 Aluminum Alloy

• Composition (%):

  • Copper (Cu): 3.8–4.9

  • Magnesium (Mg): 1.2–1.8

  • Manganese (Mn): 0.3–0.9

  • Aluminum (Al): Balance

• Tensile Strength: 470 MPa (T3 temper)

• Density: 2.78 g/cm³

Key Features:

• Excellent strength-to-weight ratio

• Good fatigue resistance for repeated stress loading

• Suitable for structural components that experience vibration and dynamic forces

Common Applications:

• Aircraft fuselage skins

• Wing tension members

• Bulkheads and ribs

• Rivets and fasteners

Although 2024 has lower corrosion resistance, it is often clad with pure aluminum (Alclad 2024) to enhance surface protection while maintaining strength.

4. The 6000 Series – Aluminum-Magnesium-Silicon Alloys (General Purpose and Structural Applications)

The 6000 series aluminum alloys are known for their balanced strength, corrosion resistance, and excellent workability. They are commonly used in aircraft parts that do not require extreme strength but must maintain good corrosion performance and weldability.

Example: 6061 Aluminum Alloy

• Composition (%):

  • Magnesium (Mg): 0.8–1.2

  • Silicon (Si): 0.4–0.8

  • Copper (Cu): 0.15–0.4

  • Chromium (Cr): 0.04–0.35

• Tensile Strength: 310 MPa (T6 temper)

• Density: 2.70 g/cm³

Key Features:

• Excellent corrosion resistance

• High toughness and weldability

• Easily extruded or machined

Common Applications:

• Aircraft fittings

• Hydraulic and fuel lines

• Small structural components

• Fixtures and tooling

Although not used in critical load-bearing structures, 6061 remains a standard aluminum grade in general aviation and maintenance operations for its versatility and low cost.

5. The 7000 Series – Aluminum-Zinc Alloys (High Strength for Modern Aircraft)

The 7000 series aluminum alloys are the strongest among all aluminum grades used in aerospace applications. Their primary alloying element, zinc (Zn), is combined with magnesium and copper to produce extraordinary tensile strength and fatigue resistance.

Example: 7075 Aluminum Alloy

• Composition (%):

  • Zinc (Zn): 5.6–6.1

  • Magnesium (Mg): 2.1–2.5

  • Copper (Cu): 1.2–1.6

  • Chromium (Cr): 0.18–0.28

• Tensile Strength: Up to 570 MPa (T6 temper)

• Density: 2.81 g/cm³

Key Features:

• Extremely high strength-to-weight ratio

• Excellent fatigue and crack resistance

• Suitable for critical load-bearing structures

Common Applications:

• Aircraft wing spars

• Landing gear components

• Fuselage frames

• High-stress bolts and fasteners

The 7075-T6 alloy, often called the “aircraft-grade aluminum,” has been a cornerstone of aviation for decades. Modern variants such as 7050 and 7475 improve upon its toughness and stress-corrosion resistance for next-generation aircraft.

6. The 5000 Series – Aluminum-Magnesium Alloys (Corrosion-Resistant and Weldable)

The 5000 series aluminum alloys, though not as strong as 2000 or 7000 series, are prized for their superior corrosion resistance and weldability. These alloys are non-heat-treatable but can be strengthened by cold working.

Example: 5083 Aluminum Alloy

• Composition (%):

  • Magnesium (Mg): 4.0–4.9

  • Manganese (Mn): 0.4–1.0

  • Chromium (Cr): 0.05–0.25

• Tensile Strength: 275–350 MPa

• Density: 2.66 g/cm³

Key Features:

• Outstanding resistance to seawater and industrial chemicals

• Excellent weldability and formability

• Maintains strength at low temperatures

Common Applications:

• Marine aircraft hulls

• Fuel tanks and pressure vessels

• Cryogenic storage systems

While not the main “standard” alloy for aircraft structures, 5xxx series materials like 5083 and 5A06 are frequently used for auxiliary parts and corrosion-sensitive assemblies.

7. Comparison of Major Aluminum Grades Used in Aircraft