Aircraft Alloys / 8740 ANN

8740 Annealed is a nickel-chromium-molybdenum alloy melted in Electric Furnaces to aircraft quality. It is a steel with hardenability properties that provide great strength and toughness. This material comes in the annealed condition for optimum machinability before heat treat. Once heat treated and quenched this alloy is used in products where strength, toughness and wear resistance are of the upmost importance. 8740 also possess great corrosion resistance and holds up well in harsh environments. It is often used to produce high-strength forged fasteners in the aerospace industry. (UNS G87400)

Chemical Makeup

Element Min Max
Carbon, C 0.38 0.43
Manganese, Mn 0.75 1
Silicon, Si 0.15 0.35
Phosphorus, P - 0.025
Sulfur, S - 0.025
Chromium, Cr 0.4 0.6
Molybdenum, Mo 0.2 0.3
Nickel, Ni 0.4 0.7
Copper, Cu - 0.35
Aluminum, Al 0.02 0.05
Vanadium, V 0.02 0.08
Columbium/Niobium, Nb 0.02 0.05

Common Applications

  • Aerospace Aerospace
  • Defense Defense


  • Good Strength
  • Good Toughness
  • Good Hardenability
  • Good Corrosion Resistance
  • Good Wear Resistance
  • Good Machinability

We stock 8740 ANN to the following specifications:

  • AMS-2301
  • AMS-2304
  • AMS-6322
  • AMS-S-6049 EXC. SONIC
  • ASTM-A-331
  • MIL-S-6049 EXC. SONIC

Click on a cross-section to see the sizes we stock:

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