The preload force should be selected on the basis of the desired result. If the preload is too high, this will result in excessive heat, thereby decreasing speed capability and bearing lifetime. If the preload is too light, this could lead to a sliding movement between balls and raceway during operation, thereby reducing the bearing life time. The required preload can be estimated by the following calculation;

Note: This estimation is not applicable for the situation of high stiffness requirement, change of load direction and appearance of undefined shock loads.