ISO 21250-1:2020

This document specifies: — basic principles, testing assembly and the test machine for noise testing of rolling bearing greases; — symbols used in the test methods BQ+, MQ and NQ. This document is applicable for testing rolling bearing greases, especially of unused grease. NOTE Suitable greases are greases of NLGI classes 1 to 3 according to DIN 51818[6]. Suitable greases for lubrication of rolling bearings are especially greases according to ISO 12924. The test method according to this document delivers meaningful results for rolling bearings; however, it can also be applied for greases in similar applications[12][13].