National Precision Bearing is a manufacturer of miniature bearings in inch, metric, specialty and dental series'.  The inch series miniature bearings are single row ball bearings available from .0400 through .7500 inch bore sizes.  The metric series are available from 1 mm to 10 mm bore sizes. The specialty series includes angular contact, modified dimensions and high-speed medical and dental bearings. They are available in stainless steel and come in both open and shielded configurations.