ThePipingMart Blog Grades AMS 4308 Aluminum Alloy – Composition Properties and Uses

AMS 4308 Aluminum Alloy – Composition Properties and Uses

AMS 4308

AMS 4308 is one of the most widely used materials in the aerospace industry. It is known for its excellent mechanical properties, making it an ideal choice for various aerospace applications. This blog post will explore AMS 4308’s composition, physical properties, mechanical properties, hardness, and heat treatment methods.

What is AMS 4308?

AMS 4308 is a specification developed by the Aerospace Material Specification Committee that outlines the requirements for high-strength alloy for Aircraft Landing Gear. This specification ensures that the alloy-producing landing gear components meet the highest strength, durability, and wear resistance standards. AMS4308 compliance is a mandatory requirement for any landing gear applied in the aviation industry. The standard goes beyond the typical requirements for high-strength alloys, so any producer aiming to comply with this spec must adhere to extremely rigorous testing and validation procedures. These procedures ensure that the material used for producing the landing gear is of the highest quality and can withstand harsh environmental conditions and exposure to various types of stress during its functional life.

AMS 4308 Composition

AMS 4308 is a nickel-based alloy primarily composed of nickel, chromium, iron, and molybdenum. It also has small quantities of other elements such as tungsten, cobalt, manganese, phosphorus, and sulfur. The alloy’s composition varies depending on the manufacturer and intended use, but it provides excellent heat and corrosion resistance.

AMS 4308 Physical Properties

The physical properties of AMS 4308 are essential to understand before using this material in various aerospace applications. The alloy has a density of 8.19 g/cm³, a melting point of 1395°C, and a thermal conductivity of 13.5 W/m·K for 25°C. Additionally, the material’s coefficient of thermal expansion is 12.8 μm/m·K, indicating that it undergoes significant expansion when heated.

AMS 4308 Mechanical Properties

AMS 4308 has high mechanical strength, making it ideal for applications that require a material with exceptional toughness. The alloy’s tensile strength ranges between 1034-1276 MPa, with a yield strength of 758 MPa. It has a relatively low modulus of elasticity of 196 GPa, indicating that it deforms more than other materials under load. It also exhibits excellent flexibility, with an elongation of 15%.

AMS 4308 Uses

AMS 4308’s mechanical and physical properties make it an ideal material for various aerospace applications. It is commonly used in manufacturing combustion chambers, turbine components, and exhaust system parts in aircraft. It is also used in nuclear power plants due to its excellent corrosion resistance in high-temperature environments.

AMS 4308 Hardness

AMS 4308 is considered a hard material with a Rockwell hardness of 32-40 HRC. Due to its hardness, it is challenging to machine, and special care must be taken to avoid compromising the material’s mechanical properties. Machined parts must be inspected carefully to ensure no undue stress or strain is present.

AMS 4308 Heat treatment

AMS 4308 can be heat-treated to achieve specific mechanical or physical properties. The material’s annealing temperature ranges between 1010-1080°C, after which it is air-cooled or furnace-cooled. Depending on the desired properties, it can also be subjected to precipitation hardening, solution treatment, ageing, or stress relief. Heat treatment must be carefully monitored to avoid compromising the material’s mechanical properties.


AMS 4308 is a nickel-based alloy with excellent mechanical, physical, and corrosion-resistant properties, making it an essential material in the aerospace and nuclear power industries. Its composition, physical and mechanical properties and uses make it an ideal choice for specific applications. However, its hardness and difficulty in machining make careful handling essential. Heat treatment methods can be used to modify their properties to fit a specific application’s requirements. Overall, AMS 4308 remains a versatile and critical material in modern industry.

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