Specification :

-Description
Ball or rollers are used to prevent or minimise rubbing
-Friction
Rolling coefficient of friction with steel can be ~ 0.005 ( adding resistance due to seals, packed grease, preload and misalignment can increase friction to as much as 0.125)
-Stiffness
Good, but some slack is usually present
-Speed
Moderate to high ( often requires cooling)
-Life
Moderate to high ( depends on lubrication, often requires maintenance)
-Cautions
Used for higher moment loads than plain bearings with lower friction