SKF bearings fatigue life in General refers to certain technical conditions (structure, process state, fit, install, clearance and lubrication) ball bearing, under actual service conditions of the host running until the rolling surface fatigue and host requirements cannot be met, the bearing inner and outer rings (shaft seat) – the total value of the relative frequency of rotation speed. When bearing a more or less constant or known, fatigue life can be used with the running total of the total number of transfer hours to represent and, in addition, it should also be noted:
　　1, factors that affect fatigue life of bearing is very much, cannot all be estimated or be eliminated through standard testing conditions, resulting in fatigue life of SKF bearings are very discrete, so the expression parameter is a rating life of bearing fatigue life L10, meaning in ISO recommendation for clearly defined as follows:
　　"On plenty of the same group of bearings in the number, transfer its rating life L10 (or unchanged in speed is expressed in hours, 90% of the bearing before the fatigue spalling can reach or exceed this speed (or hours)". So far, countries all over the world to comply with the above requirements.
　　In the United States in a number of countries, also use the concept of value in life. Same life LM refers to a group of SKF bearings, values of life, meaning before the 50% of bearing fatigue peeling able to meet or exceed the total number of go, number of working from time to time or at a certain speed, value life LM is not a bearing life of the arithmetic mean. LM value life in General is about 5 times the rated life.
　　2, rated life expectancy only applies to the concept of a sufficient number of bearing, and not to the individual bearing.
　　For example, a set of 40 bearing by its use in spite of its rated life is 1000h and not fatigue damage, may be less for the remaining 4 sets of 1000h the fatigue failure of bearings occurs, rating fatigue life of significance on behalf of these bearings in normal life expectation at the time of its material potential. Therefore, in most cases, users select a bearing fatigue life calculation is still first, again based on check of the actual failure categories, such as checking the wear life, take the calculation results in a smaller value for calculation of bearing life.