Adapter sleeves enable bearings to be mounted on smooth shafts as well as on stepped shafts. Mounting is made easier and no additional location on the shaft is required. Expensive machining of the shaft can also be avoided. For mounting bearings on stepped shafts, it is possible to use withdrawal sleeves as well. All high quality sleeves contribute to optimal bearing performance and long service life.
Tapered seat direct on journal is however recommended when the bearings run at high speed and/or high running accuracy is required.