ThePipingMart Blog Grades SAE AMS-S-6709 – Composition, Properties and Uses

SAE AMS-S-6709 – Composition, Properties and Uses


AMS-S-6709 is a specification for a premium grade of stainless steel used in aerospace and defence industries. This specification outlines the requirements for seamless tubing, wire, forgings and other stainless steel forms used in harsh environments, such as aerospace engines, oil and gas pipelines, and chemical processing plants. This post aims to provide a comprehensive guide on AMS-S-6709, covering its composition, physical and mechanical properties, uses, hardness, and heat treatment.

What is AMS-S-6709?

AMS-S-6709 is a specification that defines the requirements for the quality and testing of steel bars and forging stock. If you’re not in the steel manufacturing business, this might not sound like the most exciting topic. But think about it for a moment! These specifications are necessary for the safety and functionality of countless products to be protected. You wouldn’t want to drive in a car that used subpar steel, would you? It shows the importance of having strict standards and regulations in all industries. So, the next time you pick up a tool or get in a vehicle, remember the work that went into ensuring its quality and safety!

AMS-S-6709 Composition

AMS-S-6709 is precipitation-hardening stainless steel, also known as PH stainless steel. It comprises mainly iron, chromium, nickel, and copper, with small amounts of titanium and aluminium. The high content of chromium makes it highly resistant to corrosion and oxidation. The addition of copper provides excellent strength and flexibility. Together with titanium and aluminium, it enables the precipitation process that leads to the exceptional mechanical properties of AMS-S-6709.

AMS-S-6709 Physical Properties

AMS-S-6709 has excellent physical properties that make it suitable for challenging environments. It has a density of 0.282 lb/in3 and a melting point of 2480 °F. The thermal conductivity of AMS-S-6709 is 9.9 BTU/hr-ft-°F, and its specific heat capacity is 0.12 BTU/lb-°F. These physical properties enable AMS-S-6709 to withstand high temperatures, resist corrosion, and conduct heat efficiently.

AMS-S-6709 Mechanical Properties

The exceptional mechanical properties of AMS-S-6709 make it a valuable material for critical applications. It has a strength-to-weight ratio of 206 kip-in/lb, a tensile strength of 185 ksi, and a yield strength of 170 ksi. Its flexibility is also noteworthy, characterized by an elongation of 10% and a reduction in area of 15%. These mechanical properties make AMS-S-6709 ideal for use in aerospace parts and other critical applications.

AMS-S-6709 Uses

AMS-S-6709 is used in many applications that require high strength, corrosion resistance, and durability. One of its primary uses is in aerospace engines, which create critical parts like blades, vanes, and shafts. It is also used in oil and gas pipelines, chemical processing plants, and marine applications, where it can withstand corrosive environments and high temperatures. Its high strength and excellent flexibility make it ideal for precision machining and forging.

AMS-S-6709 Hardness

The hardness of AMS-S-6709 is measured on the Rockwell scale, and it falls between HRC 38 and HRC 44. This range of hardness gives the material an excellent balance of strength and flexibility, making it suitable for challenging environments.

AMS-S-6709 Heat treatment

AMS-S-7108 treatment is an important process that enhances the mechanical properties of AMS-S-6709. The heat treatment process involves heating the material to a specific temperature and then cooling it in a controlled manner. This process is necessary to age the material to achieve its full potential. It enables the precipitation process, ensures uniform distribution of the alloying elements and reduces the risk of distortion. The AMS-S-7108 treatment improves the strength, flexibility, and toughness of AMS-S-6709.


In summary, AMS-S-6709 is premium-grade stainless steel with high strength, excellent elasticity, and resistance to corrosion and high temperatures. Its composition and physical and mechanical properties make it ideal for critical applications in aerospace engines, oil and gas pipelines, chemical processing plants, and marine environments. The exceptional balance of strength and flexibility makes it a valuable material for forging and precision machining. The AMS-S-6709 heat treatment process enhances its mechanical properties, improves uniformity, and reduces the risk of distortions. Choosing AMS-S-6709 for your next project will guarantee the quality and durability of the final product.

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