In order to maximize the number of bearing running hours, it is most important to prevent the formation of rust on the bearings. Most bearings are subject to humidity because of outdoor use or exposed to temperature differences during day and night, causing bearings to rust. Therefore, a good quality grease should also protect the bearing from rust in extreme situations.
In order to be able to determine good rust protective greases from poor ones and therefore recommend the best quality greases for its bearings, SKF developed the EMCOR grease test rig.