The basic dynamic load rating C applied to calculate the bearing under dynamic stress, that is subjected to the rotation under load bearing. The expression shows reach ISO281: 1990 load bearing basic rating life of one million rpm. The size and direction of the load is assumed constant. For the radial bearing load of pure radial load, the thrust bearing is the axial load bearing center.

Rolling defined life as before in one of the bearing rings or metal fatigue (flaking or fracture) signs first appeared on the rolling element bearings can be achieved revolutions.

Practice has proved that, on the same surface of the bearing under the same operating conditions, will still achieve a different life. Therefore, in the calculation of the bearing size, must the term "life" is more clearly defined. All information about the general basic rated dynamic load provided is based on the same surface of the bearing of a sufficiently large number, more than 90% can be achieved as the basis of life.

There are several different definitions of bearing life. One of them is "working life", said the actual attained before the bearings under actual working conditions, failure of life. It must be noted that individual bearing life can only be predicted by statistical methods. Bearing life calculation only for groups and reliability in terms of certain procedures, about 90%. Failures occur in actual use is not usually caused by fatigue, the situation is more contamination, wear, misalignment, corrosion caused by failure to maintain or another cage, lubricant or seals caused.

Another "life" is "the life of the agreement", formulated by the party lawsuit or industry sector standard-setting bodies specified based on an assumed working load and speed conditions. This is essentially a basic rating life of the bearing, generally based on the experience of similar applications come dependent.