Bearing Steels - AMS 6414 / 6415 - 4340

AMS 6414 / 6415 - 4340

4340 vac AMS 6414 is a low alloy steel, maintaining high strength when heated. Typical applications of 4340 AMS 6414 include the aerospace and defense industries for structural use, including aircraft landing gear and power transmission gears. It offers good machinability in the normal, annealed or tempered conditions.

The high fatigue strength makes this alloy ideal for highly stress parts due to it's ability to maintain it's strength and hardness at increased temperatures.

Chemical Composition

Spec: AMS 6440/6444

Chemical Element % Present
Carbon (C) 0.40 max
Chromium (Cr) 0.80 max
Manganese (Mn) 0.0 - 0.75
Silicon (Si) 0.0 - 0.30
Molybdenum (Mo) 0.0 - 0.25
Nickel (Ni) 0.0 - 1.80
Iron (Fe) Balance


Physical PropertyValue
Density 7.84 g/cm³
Thermal Conductivity 37.48 W/m.K



Mechanical PropertyValue
Tensile Strength 1905 MPa
Elongation A50 mm 11 %

Supplied Forms

  • Bar
  • Rod
  • Forgings
  • Plate
  • Wire


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Last Datasheet Revision

18 July 2019


This Data is indicative only and as such is not to be relied upon in place of the full specification. In particular, mechanical property requirements vary widely with temper, product and product dimensions. All information is based on our present knowledge and is given in good faith. No liability will be accepted by the Company in respect of any action taken by any third party in reliance thereon.

Please note that the 'Datasheet Update' date shown above is no guarantee of accuracy or whether the datasheet is up to date.

The information provided in this datasheet has been drawn from various recognised sources, including EN Standards, recognised industry references (printed & online) and manufacturers’ data. No guarantee is given that the information is from the latest issue of those sources or about the accuracy of those sources.

Material supplied by the Company may vary significantly from this data, but will conform to all relevant and applicable standards.

As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose, whether expressed or implied.

Advice given by the Company to any third party is given for that party’s assistance only and without liability on the part of the Company. All transactions are subject to the Company’s current Conditions of Sale. The extent of the Company’s liabilities to any customer is clearly set out in those Conditions; a copy of which is available on request.