ASTM D8503-23

5.1?This test method can be used to determine scuffing temperature limit and the evolution of coefficient of friction of lubricating oils with increasing temperatures for use in tribological contacts in which high-speed vibrational or start-stop motions are present for extended periods of time under initial high Hertzian line contact pressures. It has found application as a screening test for engine oils, gear lubricants and turbine oils. The test temperature may reach up to 300 ?C. Users of this test method should determine whether results correlate with field performance or other applications. In comparison to the ball-on-disk geometry in accordance with Test Method D6425, the initial contact pressure is better retained over test time in this roller-on-disk geometry.

1.1?This test method covers the determination of a scuffing temperature limit of lubricating oils at prescribed conditions and the retention of friction over temperature load step increases in a roller-on-disk (flat) geometry when subjected to high-frequency, linear oscillation motion. This test method is executed under constant load, frequency and stroke in a SRV test machine. The evolution of coefficient of friction of lubricating oils as function of temperature is recorded and assessed.

1.2?Tribometrical scuffing tests were so far related to load step tests. This test method determines the upper temperature limit for operating a lubricant and can also be used to determine the ability of a non-EP lubricating oil to protect against scuffing with increasing temperature.

1.3?The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4?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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.