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Dynaroll Ball Bearings: Bearing Cages and Retainers



The retainer, also referred to as the cage or separator, is used to separate and position the balls at equal intervals around the bearing raceways. Retainers are available in two standard types, according to the size and design of the bearing itself. The most common is a 2-piece closed ball pocket design known as a ribbon retainer. The crown retainer is a single piece open ball pocket design. For most bearing sizes, the retainer type is as shown in the individual bearing tables, and cannot be specified by the user. However, for special applications, please contact a Dynaroll engineer to discuss retainer options.


J TYPE RIBBON RETAINER The closed pocket design of the ribbon retainer is the most common type. The material used is 300 series stainless steel. For low torque applications, a loose clinched ribbon retainer may be available.  
W TYPE CROWN RETAINER The standard metal crown retainer is very light weight, with specially coined ball pockets to reduce torque and provide smooth running characteristics. Material used is 400 series stainless steel.

T12 TYPE CROWN RETAINER Plastic crown retainers have the highest speed ratings of any standard retainer type, but have limited availability.


RETAINER MATERIAL Retainer materials other than the standard 300/400 series stainless steel or plastic are available for specific applications. Please contact Dynaroll concerning availability and compatibility of different retainer types.