ASTM D2509 test method for load-carrying capacity of lubricating grease
ASTM D2509 standard test method for measurement of load-carrying capacity of lubricating grease (Timken method)
1. Scope
1.1 This test method covers the determination of the load-carrying capacity of lubricating greases by means of the Timken Extreme Pressure Tester.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see 7.1, 7.2, and 9.4.
2. Referenced Documents
2.1 ASTM Adjuncts:
ADJD2509, Glossy Prints of Test Blocks Showing Various Types of Scar
3. Terminology
3.1 Definitions:
3.1.1 load-carrying capacity, of a lubricating grease, n - the maximum load or pressure that can be sustained by a lubricating grease without failure of the sliding contact surfaces as evidenced by seizure or welding.
3.1.1.1 Discussion - The values of load carrying capacity of a lubricating grease vary according to test method.
3.1.2 scoring, in tribology, n - a severe form of wear characterized by the formation of extensive grooves and scratches in the direction of sliding.
3.1.2.1 Discussion - When the lubricant film is substantially maintained, a smooth scar is obtained on the test block, but when there is a breakdown of the lubricant film, scoring or surface failure of the test block takes place as shown in Fig. 1. In its simplest and recognized form, scoring is characterized by a wide scar on the test block and by the transfer of metal from the test block to the contacting surface of the test cup. The form of surface failure more usually encountered, however, consists of a comparatively smooth scar, which shows local damage that usually extends beyond the width of the scar. Scratches or striations that occur in an otherwise smooth scar and that do not extend beyond the width of the scar are not considered scoring in this test method.
3.1.3 seizure or welding, n - localized fusion of rubbing metal, usually indicated by streaks of transferred metal, increased friction and wear, or unusual noise and vibration.
3.1.4 wear, n - the removal of metal from a rubbing surface by mechanical action, or by a combination of mechanical and chemical actions.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 OK value, n - the maximum mass (weight) added to the load lever mass (weight) pan, at which no scoring or seizure occurs.
3.2.2 score value, n - the minimum mass (weight) added to the load lever mass (weight) pan, at which scoring or seizure occurs.
