Technical Benefits of Age Hardening Specific Steel Grades per AMS 2759/3

Welcome to our in-depth discussion on the age hardening of specific steel grades as outlined in AMS 2759/3. Age hardening, or precipitation hardening, is a specialized heat treatment process that enhances the mechanical properties of certain materials. By adhering to the stringent standards set out by AMS 2759/3, which covers age hardenable steel grades such as 17-4 PH (UNS S17400), AM 350 (UNS S35000), A-286 (UNS S66286), and AerMet 100 (UNS K92580) among others, you are assured of the best material performance and quality.

Improved Mechanical Properties:

  • Strength & Hardness: After aging the steels covered by AMS 2759/3 exhibit enhanced tensile strength and hardness, ensuring materials can handle higher mechanical stresses without deforming.
  • Ductility: Unlike many other steel alloys, after age hardening some grades will exhibit both improved strength and ductility, leading to a strong yet tough final product.

Enhanced Wear Resistance:

The increased hardness and development of fine precipitants resulting from the aging process of these specific grades can lead to superior wear resistance. This ensures that components crafted from such materials offer a longer operational life and reduced maintenance due to wear.

Stability at Elevated Temperatures:

The steel grades outlined in AMS 2759/3, when age-hardened, keep their enhanced mechanical properties at elevated temperatures. Some grades can retain their mechanical strength at operating temperatures more than 1000°F. This is essential for components used in high-heat applications, promising strength, and structural soundness.

Controlled Grain Growth:

The AMS 2759/3 standard stipulates precise directives for grain size and morphology management during heat treatment. A finer, more uniform grain structure leads to better mechanical properties and consistent results across batches.

Predictable & Consistent Outcomes:

By carefully following the precepts of AMS 2759/3, we ensure delivery of predictable and consistent outcomes. This degree of uniformity reduces variability and ensures batch to batch consistency supplying the needed properties every time.

Cost-effective Production:

Given their enhanced properties, components from these steel grades can be designed with reduced thickness, leading to significant weight and cost reductions. The long-lasting and wear-resistant nature of age-hardened parts also reduces the replacement frequency, ensuring long-term financial benefits.


Many of the grades covered by AMS 2759/3 can be aged to a number of different conditions allowing for substantial versatility of application using the same material.


The age hardening of steel grades as defined in AMS 2759/3 offers many technical benefits, from improved mechanical properties to fiscal advantages. By adopting this standardized procedure our customers are supplied superior products to withstand the most challenging of operational scenarios. Whether you’re involved in aerospace, automotive, or any demanding sector, you can trust ThermTech to supply the most effective and consistent heat treatment.

ThermTech—Experts in Austempering Stampings, Machined Parts, and Investment Castings

ThermTech, Inc. offers both small and large batch capabilities for austempering steel and iron investment castings. Between our neutral salt bath furnaces and our larger austempering furnaces, we have the capabilities to austemper a wide variety of stamping, machined components, and investment castings. We have run austempering on alloys from 1060 through 4340 to ductile iron machined parts.

Our dedicated team works with you to ensure we meet your specifications. Count on our decades of experience with hardening, tempering, surface heat treatments, vacuum treatments, and annealing. To learn more about our services, please contact us today.

Learn more about austempering and how ThermTech can serve you by watching these videos.

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