What are some common ball bearing sizes?

Common ball bearing sizes include 3/16-inch bore, 1.5-inch bore and 9-millimeter bore. Each ball bearing is rated according to how much weight it can accommodate in three different categories: radial load, thrust load and combined load.

Ball bearings reduce the friction caused when load-bearing mechanical surfaces make contact. To maintain devices with ball bearings properly, people must regularly lubricate the ball bearings and check the balls for signs of wear and tear. Because ball bearings roll freely in their ball races, ball damage onsets slowly. It is generally wise to discard any balls that have developed sharp or rough spots.