The Magneto bearing is a separable grooved ball bearing. The inner ring raceway groove of magneto bearings is slightly shallower than that of deep groove bearings. The outer ring raceway has only one raceway shoulder and smooth transition to the open side.
With this raceway construction the outer ring is separated, allowing easier mounting. In general, two of these bearings can be used together in a paired mounting (duplex pairs). Magneto bearings are small bearings with a bore diameter of 4 to 20 mm and pressed brass cage as standard, though machined synthetic resin cages can be used for high-speed rotation.