Mechanical extractors can be used to dismantle small and medium sized rolling bearings that are located with a tight fit on a shaft or in a housing. The bearing can be dismantled without damage if the extractor is in contact with the tightly-fitted bearing ring. In the case of mechanical extractors, the extraction force is normally applied by means of threaded spindles. In addition to the two-arm and three-arm devices as well as a hydraulic pressure tool, special solutions are also possible. For dismounting of larger bearings, hydraulic extractors should be used.
These mechanical tools are designed for the mounting and dismounting of bearings. The mounting forces are transmitted by the geometrical locking effect.