MIL-PRF-81322 Silicone

MIL-PRF-81322 silicone is for aircraft grease that meets the requirements of MIL-PRF-81322, a U.S. military specification for NATO Code G-395. This performance specification covers general-purpose aircraft grease and is not specifically about silicone elastomers or silicone greases.

MIL-PRF-81322 Greases

The current version of the specification, MIL-PRF-81322G, includes these key requirements.

  • Greases must be formulated using a liquid lubricant (oil) and a gelling agent (thickener) such that the resulting compound performs over a wide temperature range, including extremes (temperatures from about –54 °C up to about +177 °C) in aircraft environments.
  • Physical properties include minimum/maximum limits for dropping point (232 °C minimum), evaporation loss (after 22 h at 177 °C: ≤10% weight loss), oil separation after 30 h at 177 °C (2–8% weight loss), and water washout loss at 41 °C (≤20%).
  • Mechanical / performance tests include low-temperature torque (at –54 °C: starting ≤0.98 Nm; after 60 minutes running ≤0.098 Nm), bearing life at 177 °C (minimum 400 hours) in ASTM D3336 test, and load‐carrying capacity (load wear index ≥30 in ASTM D2596.
  • Compatibility: The grease must be compatible with previously qualified greases when mixed (tested per the spec).
  • Qualification: Only products authorized by the qualifying activity and listed on the Qualified Products List (QPL-81322) may be used for contract awards. Any change in formulation triggers requalification.

MIL-PRF-81322 Applications

MIL-PRF-81322 silicone is used under challenging aviation and aerospace conditions. Common applications include:

  • Wheel bearings, landing gear mechanisms, rotor bearings (helicopters) where speeds are high, loads are heavy and temperature extremes are encountered.
  • Control system actuators, screw-jacks, servo mechanisms, static/dynamic joints, electric motors on aircraft where lubricant viscosity, film strength, water/washout resistance and seal‐compatibility matter.
  • Aerospace environments including marine (shipboard), extreme cold altitude/far-north conditions and elevated temperature engine compartments.

Ask ElastaPro for MIL-PRF-81322 Silicone

ElastoPro produces MIL-STD-417 silicone at our Made in USA manufacturing facility, and in accordance with our ISO 9001:2105 and AS9100D certified Quality Management System (QMS). Contact us to request a quote, or for more information.