NSK 684zz Bearing
Precision Ball Bearings
Miniature Precision Ball Bearings for Specialized Industries. Miniature Precision Bearings are identified by having an internal diameter of less than 3/8 inches (9.5 mm) while still containing the same components used in standard radial ball bearings.Higher precision bearings are available in ball bearings, angular contact ball bearing, ball screw support bearings, cylindrical roller bearings, spherical roller bearings and tapered roller bearings. The most common high precision bearing is the angular contact bearing, also referred to as a spindle bearing.
Precision Ball Bearings . Shielded. Sealed. For greater accuracy and higher speeds, these bearings are made to tighter tolerances than standard ball bearings. Shielded bearings dissipate heat more efficiently than sealed bearings. Sealed bearings block out dust and other contaminants better than shielded bearings.