Insert bearings are designed to be mounted on shafts without using lock nuts, adapters, or shoulders. The inner ring of the insert bearing frequently extends outside of both sides of the housing to provide extra support to the shaft. Typically, these bearings come pre-lubricated with a multi-purpose lithium based grease, and allow for re-lubrication. Insert bearings are also available in free spinning design and a black oxide finish upon request. They are most commonly produced with a spherical OD to allow for misalignment, but are also available with a cylindrical OD.National Precision offers a variety of insert bearings that can be used in numerous applications. Bearing inserts are used to replace worn or damaged bearings in an existing bearing housing without needing to repurchase a new mounted housing. In some cases, the mounted unit does not need to be removed from mounted surface.