5.1 The significance of the number of scratches as far as correlation with field performance is concerned has not been established. A particle which is abrasive to plastic will not necessarily be abrasive to steel or other bearing materials. Some correlation was obtained in that the contaminant used in Sample 3 (see 10.1.1) had a greater wear rate in a laboratory ball bearing abrasive wear test than the contaminant in Sample 2.

Note 1: The number of scratches obtained cannot be used to draw fine differences between greases, but rather, to group them into two or three general classes. One such possible division could be:

1 ... . less than 10 scratches

2 ... . 10 to 40 scratches

3 ... . more than 40 scratches

5.2 An advantage of this test method is that each test takes only a few minutes to run.

5.3 This test method is used for quality control and specification purpose.

1.1 This test method covers a procedure for the detection and estimation of deleterious particles in lubricating grease.

1.2 This test method is applicable to all lubricating greases. It can also be used to test other semi-solid or viscous materials. Grease fillers, such as graphite and molybdenum disulfide, can be tested for abrasive contaminants by first mixing them into petrolatum or grease known to be free of deleterious particles.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Within the text, the SI units are shown in brackets.

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 and health practices and determine the applicability of regulatory limitations prior to use.