ASTM D2266 for wear preventive characteristics of lubricating grease
ASTM D2266 standard test method for wear preventive characteristics of lubricating grease (Four-Ball method)
6. Apparatus
6.1 Four-Ball Wear-Tester and Accessories - See Fig. 1 and Fig. 2.
NOTE 3 - It is important to distinguish between the Four-Ball EP Tester and the Four-Ball Wear Tester. The Four-Ball EP Tester is designed for testing under heavier loads and more severe conditions; it lacks the sensitivity necessary for performing four-ball wear test.
6.2 Microscope, capable of measuring the diameters of the scars produced on the three stationary balls to an accuracy of 0.01 mm. It is more efficient to measure the scars without removing the three balls from the holder.
7. Reagents and Materials
7.1 Test Balls, chrome alloy steel, made from AISI standard steel No. E-52100, with diameter of 0.5 in. (12.7 mm), Grade 25 EP (Extra Polish). Such balls are described in ANSI Specifications B 3.12, for Metal Balls. The Extra-Polish finish is not described in that specification. The Rockwell C hardness shall be 64 to 66, a closer limit than is found in the ANSI requirement.
NOTE 4 - Steel balls meeting this description were used in developing the precision of the test.
7.2 Cleaning Fluids for preparing balls and apparatus for the test should be those capable of removing metal preservative coating from the balls, eliminating carryover effects from one test to the next. The cleaning fluid selected should be non-film-forming and not contribute to the wear or antiwear properties of the test lubricant. (for example, chlorinated solvents should not be used.)
8. Test Conditions
8.1 The test shall be conducted under the following conditions:
Temperature 75 more or less 2°C (167 more or less 4°F)
Speed 1200 more or less 60 rpm
Duration 60 more or less 1 min
Load 40 more or less 0.2 kgf (392 more or less 2 N)
NOTE 5 - Although the test can be run under other conditions, the precision limits described in Section 11 apply only to tests conducted under the conditions described in Section 8.
9. Preparation of Apparatus
9.1 Set up the drive of the test machine to obtain a spindle speed of 1200 more or less 60 rpm.
9.2 Set the temperature controller to maintain a test temperature of 75 more or less 2°C [167 more or less 4°F].
9.3 When an automatic timer is used to terminate a test, it should be checked for the required more or less 1 min. accuracy at 60 min. elapsed time.
9.4 The loading mechanism must be balanced to a zero reading with all parts and test grease in place. To demonstrate proper precision, an addition or subtraction of 0.2 kgf (19.6 N) should be detectable in imbalance. Determination of accuracy of loading at 40 kgf (392 N) is difficult and generally is limited to careful measurement of lever-arm ratios and weights with dead-weight loading apparatus or piston diameter and calibration of pressure gage with pneumatic loading systems.
