ASTM G 223 : 2023

1.1This test method covers laboratory procedures for determining the coefficient of friction (COF) and resistance of materials to adhesion under flat sliding using the twist compression test (TCT). This test method ranks material couples, surface treatments, coatings, and lubricant combinations by COF and their resistance to adhesion.

1.2The time until adhesion for the materials under the test conditions are reported and used to quantify the tribocouple’s adhesion resistance and susceptibility to galling or scuffing. Systems of higher adhesion resistance will give longer time until failure.

1.3The coefficient of friction values averaged between the test reaching full test pressure and the time of the onset of adhesion or the end of tests run for a predetermined time period are recorded. Systems are ranked by their average coefficients of friction before adhesion occurs.

1.4Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard except psi and pounds in Table 1.

1.5This 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.

1.6This 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.