The profiling of rolling elements to avoid stress concentrations at their ends has been standard industry practice for years, but the geometry of the profile and the resultant effect on the life of the bearing can vary. Split bearing specialist, Cooper Bearings has fine-tuned the roller profile of its most popular size range and now uses the theoretical optimum logarithmic profile roller, which can extend L10 life by 25%. The logarithmic profile can be proportioned to give sufficient depth of relief to be effective at high peak loads and make better use of the roller length at low loads, compared with conventional profiles.