Deep groove ball bearing are most commonly used rolling bearings. Kai Rui Machinery Parts Co.,Limited stocked large quantities of ball bearings, they are available from from miniature ball bearings with outside diameter of less than 9mm to extra-large bearings that exceed 1, 500mm in diameter. Small and mid. size bearings are also available in a variety of shield, seal and snap ring arrangements. Big ones normally are fitted with solid brass or steel cages.