In general, the cages used in NSK miniature bearings are either ribbon cages or snap cages, both made of pressed steel. Pressed steel ribbon cages are generally used in the larger bearings and pressed snap cages in the smaller ones. In recent years, plastic snap cages, which have the advantages of low torque, long grease life, and low noise, have been used in many kinds of miniature ball bearings. The table as below show the various types of cages and their symbols (refer to NSK miniature bearing nomenclature.

Type	Symbol	Name
	J	Pressed steel ribbon cage
	W	Pressed steel snap
	T12 T1X	Plastic snap cage