Insert bearings and wide inner ring bearings are used for mounting on shafts without the need for shoulders, locknuts, or adapters. The bearing is locked in place through setscrews or a locking collar. The inner ring usually extends on both sides of the bearing to provide extra shaft support.

A related style of insert bearings is the wide inner ring bearing. The wide inner ring, or double extended inner ring insert features an inner ring that extends beyond the width of the outer ring on both sides of the insert. The extension on one side accommodates a heavy-duty seal. The other side is extended even further to accommodate both a heavy-duty seal and the locking device. Wide inner ring insert bearings also distributes the load over the larger surface area created by the wider inner ring.

These bearings are generally used for heavier duty applications. Generally, insert bearings are standard radial bearings that have been adapted to fit into a housing. Although they are generally sold with the housing, these bearings may also be purchased as stand-alone products to use as replacements.

While standard radial ball bearings must be pressed into a machined shaft, using special installation tools, insert bearings can be slip fitdirectlyonto the shaft. However, insert bearings are typically mounted onto shafts that are slightly smaller than the bearing bore diameter. Insert bearings, however, are mounted to a shaft that is typically slightly smaller than the bearing bore diameter. This loose fitting necessitates a locking device to hold the bearing securely in place. The inner ring of the bearing is extended to one side to accommodate the locking device. In addition, the width of the insert bearings inner ring may vary according to the type of the bearing.