The subject “Service Experience with Grease” can cover a wide range of application. Fortunately the manufacturing operations at Kodak Park include an extensive variety of service conditions, operating 24 hr. a day under closely controlled conditions, which afford considerable experience in a relatively short time with many of the variables affecting grease performance eliminated. The service experience described in this paper {fx79-01} has been selected as being representative of grease lubrication in many industrial plants. Our limited knowledge of grease compels selection of the various types of grease by broad, fundamental characteristics, by the reputation of the grease manufacturer together with the gossip of the trade, and finally, by trial and error in actual operation. Actual testing of grease in operating equipment is slow, costly, and subject to error in conclusions due to variables beyond practical control. Some of the obvious variables are: 1. How clean are the bearings before applying the test grease? 2. If new bearings are used, what, if any, means are there of determining the uniformity of the bearings? 3. In ball bearing electric motors, what control is there over bearing temperature? 4. Is the design of the equipment such that the same quantity of grease can be applied to the same bearing size? 5. What criteria are to be used in judging the performance of the grease? In addition to the variables in testing greases in service and judging the performance, there are other questions that the industrial users are concerned with. Among these are: 1. Just how does a grease function under any given application? 2. What affect does the type of soap and oil viscosity have on the performance of the grease? 3. What tests shall be used for lot acceptance and what tests shall be used for judging the grease in equipment? 4. Do the ordinary physical tests indicate in any way the performance to be expected? 5. Are there any accelerated tests which have been correlated with service tests?