Grease Test Method Write Ups for High-Performance Multiuse (HPM) grease specifications
Note to reader: This document was prepared by Chuck Coe of Grease Technologies, LLC for the NLGI specification work being conducted in 2019 and 2020. Questions or comments can be sent to ChuckCoe@grease-tech.com.
High-Performance Multiuse (HPM) Core Specification
Cone Penetration worked 60x (ASTM D217) [r=7, R=20 ]
Grease hardness or softness (consistency) is quantified by this test by measuring the depth in dmm that a cone penetrates a grease sample under standard conditions. The 60 stroke worked penetration value (used to assign an NLGI consistency grade) is measured after shearing the grease with a plunger assembly sixty double strokes.
Prolonged Worked Penetration (ASTM D217) [r=15, R=27]
Shear stability or mechanical stability is the ability of a grease to resist changing consistency during mechanical working, such as what may be encountered in the field. A variety of laboratory tests evaluate shear stability. In this test, the grease is subjected to shear by extended working in a grease worker and the change in penetration after the test is reported.
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