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Age / Precipitation Hardening

What is Age Hardening (Precipitation Hardening)?

Age Hardening (or Precipitation Hardening) is performed after solution treating of precipitation hardening (PH) grades of stainless steel. When PH stainless steels are heated between 900ºF and 1200ºF, secondary phase particles precipitate out of the previously formed solid solution. These particles serve as a strengthening and hardening mechanism.

Precipitation Hardening can also be performed in combination with other processes (such as nitriding) to reduce costs and offer greater benefits. 


  • High strength & hardness
  • Improved corrosion resistance
  • Retention of strength at elevated temperatures
  • Improved machinability

Common Materials & Applications for Precipitation Hardening

  • Martensitic (17-4, 15-5, etc.)
  • Semi-Austenitic (17-7, 17-7Mo, AM-350, etc.)
  • Austenitic (A-286)
  • Application examples include, but are not limited to: fasteners, engine parts, gears, shafts, bushings, valve stems and more

This Heat Treatment is Offered at at All Four AHT Locations.