11. Rating Procedure
11.1 Remove the bearing from the test jar and place the bearing cup in a 50 + 50 mixture by volume of isopropyl alcohol (Warning - Flammable) and mineral spirits, reagent grade (Warning - Combustible. Vapor harmful). The solvent mixture can be heated to facilitate the removal of the grease. Agitate vigorously to remove the grease. Repeat the rinsing using fresh solvent mixture or gently wipe the bearing with a clean cloth or tissue to ensure that traces of grease are removed.
11.2 Transfer the bearing cup from the solvent and allow to dry on clean filter paper.
11.3 Examine the cup raceway for evidence of corrosion without the use of magnification (Section 5). Use only a pass or fail rating. Criteria for failure shall be the presence of any corrosion spot 1.0 mm or larger in the longest dimension. Ignore the number of spots.
11.3.1 Spots that are easily removed by rubbing lightly with soft tissue (alone or wetted with any solvent nonreactive to rust or steel at room temperature) shall not be considered as corrosion in the rating.
12. Report
12.1 The reported result shall be the pass or fail rating as determined by at least two of the three bearings.
13. Precision and Bias
13.1 Due to the nature of the results, the precision of this test method was not obtained in accordance with RR:D02–1007, "Manual on Determining Precision Data for ASTM Methods on Petroleum Products and Lubricants."
13.2 Precision - The precision of this test method as determined by statistical examination of interlaboratory results is as follows:
13.2.1 Repeatability may be judged by the fact that 94 % of duplicate results obtained by nine laboratories with six samples were in agreement.
13.2.2 Reproducibility may be judged by the fact that nine laboratories matched consensus 96 % of the time with six samples showing good or poor protection against corrosion.
13.3 Bias - No statement is made about the bias of this test method since the result merely states whether there is conformance to the criteria for success specified in the procedure.
14. Keywords
14.1 bearing; corrosion; lubricating grease; rust
