ASTM D2596 for measurement of extreme-pressure properties of lubricating grease
ASTM D2596 for standard test method for measurement of extreme-pressure properties of lubricating grease (Four-Ball method)
4. Summary of Test Method
4.1 The tester is operated with one steel ball under load rotating against three steel balls held stationary in the form of a cradle. The rotating speed is 1770 more or less 60 rpm. Lubricating greases are brought to 27 more or less 8°C (80 more or less 15°F) and then subjected to a series of tests of 10-s duration at increasing loads until welding occurs.
5. Significance and Use
5.1 This test method, used for specification purposes, differentiates between lubricating greases having low, medium, and high level of extreme-pressure properties. The results do not necessarily correlate with results from service.
5.2 It is noted that lubricating greases that have as their fluid component a silicone, halogenated silicone, or a mixture comprising silicone fluid and petroleum oil, are not applicable to this method of test.
