CSB-EPB® plastic plain bearings recommend that the tolerance of the standard mating housing bore is H7, and the tolerance of the mating shaft is h9. This is the general standard press-fit tolerance established by combining the interference fit and the effect of the thermal expansion coefficient on the size of the plastic bearing during operation. When the dimensional tolerance of the shaft or housing changes, it will affect the size of the contact area between the shaft and the plastic bearing, and will change the actual bearing load Pact. Once the Pact of the plastic bearing changes, it will directly affect the service life of the bearing. In general, we believe that the smaller the clearance between the shaft and the engineering plastic bearing, the larger the contact surface between them, thereby extending the service life of the bearing, otherwise the contrary. Of course, when we reduce the fit clearance between the shaft and the bearing as much as possible, we must also consider the reserved clearance for normal operation of shaft.