ThePipingMart Blog Grades AMS 7718 Nickel Iron Alloy – Composition, Properties and Uses

AMS 7718 Nickel Iron Alloy – Composition, Properties and Uses

AMS 7718

AMS 7718 is a versatile material widely used in various industries due to its excellent physical and mechanical properties. This material is commonly used in aerospace, defence, and automotive sectors as it provides high strength and durability. This blog post will discuss the composition, physical and mechanical properties, hardness, and heat treatment of AMS 7718. So, let’s dive in!

What is AMS 7718?

AMS 7718 is a specification issued by the Society of Automotive Engineers (SAE) for producing high-performance nickel alloy. This particular specification is focused on ensuring the quality of nickel plates used in the aerospace and aircraft manufacturing industries. Compliance with AMS 7718 ensures the plates meet the high standards to withstand the harsh environments and stresses encountered during flight. If you are involved in the aerospace industry, being familiar with AMS 7718, and its requirements is crucial to ensure optimal performance and safety.

AMS 7718 Composition

AMS 7718 is a low-carbon steel alloy of mostly iron and carbon. It also contains small amounts of molybdenum, manganese, silicon, and phosphorus. The combination of these materials provides the balance of strength and flexibility required for various industrial applications.

AMS 7718 Physical Properties

AMS 7718 has excellent physical properties, including high toughness and fatigue resistance. It has a density of 7.85g/cm3 and a thermal conductivity of 47W/m.K. This material also has a coefficient of thermal expansion of 11.7×10-6/K, making it highly resistant to thermal stress.

AMS 7718 Mechanical Properties

The mechanical properties of AMS 7718 make it an ideal material for high-stress applications. It has a tensile strength of 1350-1450 MPa and a yield strength of 1050-1150 MPa. This material exhibits high fatigue resistance and has good impact strength, enabling it to withstand sudden shocks or loads.

AMS 7718 Uses

Due to its high mechanical and physical properties, AMS 7718 is widely used in various industries. It is commonly used to manufacture engine parts, landing gears, and aircraft suspension systems. AMS 7718 is also used to produce automotive springs and high-stress machine parts.

AMS 7718 Hardness

The Rockwell hardness of AMS 7718 ranges from 45 to 50 on the C scale. This hardness level signifies that the material has excellent strength and durability and is resistant to wear and tear. Additionally, AMS 7718 can be heat-treated to increase its hardness, making it suitable for even high-stress applications.

AMS 7718 Heat Treatment

Heat treatment is subjecting a material to high temperatures and cooling it to strengthen or improve its properties. AMS 7718 can be heat-treated to achieve different hardness levels. Heat treated at 871°C followed by water-quenching can result in a Rockwell hardness of approximately 53.


AMS 7718 is an excellent material choice for high-stress industrial applications due to its excellent physical and mechanical properties. It has a high tensile and yield strength, low density, and high toughness, making it suitable for various industries. Additionally, the ability to heat treat this material to improve its properties ensures that it can be tailored to specific applications. This is why AMS 7718 is a popular choice for many applications.

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