Cage (Retainer)

The main purpose of the cage or retainer is to separate the balls, maintaining an even and consistent spacing, and to accurately guide the balls in the raceways during rotation. NTN uses two types of cages for bearing inserts: pressed steel cages and nylon cages.

Pressed steel cages

Pressed steel cages are the most common type of cage produced by NTN. In this process, steel is formed (pressed) into the proper shape and size to fit the rolling elements, their spacing, etc. NTN insert bearing steel cages are pressed as two separate halves and riveted or welded together to form a one-piece retainer. These cages have a very high temperature capacity and are generally used in heavier duty applications.

Pressed Steel Cage

UC, UEL, UK, AS and AEL inserts use pressed steel cages. Although NTN’s suffix for a pressed steel cage is J, it is seldom used with these inserts because it is considered to be "standard," unless otherwise specified. The Ultra-Class wide inner ring mounted units specifically use UC and UEL inserts with steel cages.

Nylon cages

Nylon Cage

Nylon cages are designed as one-piece retainers and are created by an injection molding process. NTN typically uses glass-reinforced Nylon 66 for these cages: these cages more readily tolerate misalignment and are generally quieter in operation, but are limited to applications where the continuous operating temperature does not exceed 250°F (120°C). Nylon cages are considered "standard" for UR, REL, AR and JEL inserts unless otherwise specified: the suffix designation is T2, though it is rarely used in reference. The Ultra-Class narrow inner ring mounted units use only AR and JEL inserts with nylon cages.