ASTM D1478 Low Temperature Torque of Ball Bearing Grease – with Preconditioning
Preconditioning involves heating the grease sample under vacuum for 72 hours to remove volatiles, light ends and entrained atmosphere. Preconditioning of the grease is as per Boeing specification BMS 3-25C for Vaccuum Stable Lubricants Type II and Type III. The grease is exposed to a 10-6 torr, heated to 290ºF and held for 72 hours.
The preconditioned grease is then tested as usual by test method ASTM D1478 under the prescribed test conditions.