Definition

AMS 6444 is a material specification for high-strength alloy steel of the 4340 type, intended for demanding applications in the aerospace and defense industries. Compared to AMS 6440, it represents a higher-grade variant with stricter requirements for material quality, cleanliness, and manufacturing control.

Features

  • Very high strength after heat treatment
  • High toughness under dynamic and impact loading
  • Excellent fatigue resistance
  • Higher material cleanliness (lower inclusion content)
  • Stable mechanical properties under long-term loading
  • Good hardenability even in larger cross-sections
  • Suitable for critical applications with high reliability requirements

Applications

  • Highly loaded aerospace components
  • Shafts, pins, and structural load-bearing parts
  • Aircraft landing gear systems
  • Critical engine and transmission components
  • Aerospace and defense industries
  • Applications requiring maximum material reliability

Conclusion

AMS 6444 represents a higher quality standard within 4340-type steels. Thanks to stricter manufacturing control and improved material cleanliness, it is suitable for the most demanding applications where material failure is not acceptable.