Coefficient of Friction ASTM D3702

Wear Rate and Coefficient of Friction using a Thrust Washer Testing Machine ASTM D3702

This test method evaluates the performance of materials in rubbing contact under end use type conditions. The contact can be a test material against steel or against itself. The test specification refers to self-lubricating materials - external lubrication is not part of the specification. This test data would be used for the design of gears and bushings.

Test Procedure:
The test specimen is machined from a larger sample of the test material. The specimen is fixed into the sample holder using a pin and a bolt, and this assembly is inserted into the tester. Weights are added to provide the desired contact pressure, and the rotational velocity is set. A break-in period, typically 40 hours, is run to ensure intimate contact between the mating parts. The test sample is then weighed and measured, and the test begins. Contact pressure, rotational velocity (RPM), and the number of cycles (hours) must be specified for each test.

Specimen size:
Test materials are machined into a disk approximately 1.0" in diameter by 0.2" thick, with a raised wear surface.

Wear rate can be calculated as either in./hour or grams/hour. Coefficient of friction is calculated as Torque / force x specimen radius. PV limit (pressure x velocity) is the point at which the material fails catastrophically.

Equipment Used:
Falex Friction and Wear test machine

**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. For more information please contact an Intertek PTL Technical Representative at Due to copyright restrictions, we are not able to provide copies of standards. Standards can be obtained from appropriate standards authorities.

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