<div class="htmlview paragraph">Cleaner steels, advanced manufacturing techniques and the use of modern design methods have justified an increase of dynamic load ratings for cylindrical and tapered roller bearings as well as ball bearings. With the new load ratings, greater emphasis must be placed on the operating factors that influence the fatigue life of a bearing. These factors include reliability, material, lubrication, alignment and load distribution. A detailed discussion of load rating increases and the life adjustment factors is presented.</div>