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Cages

The cage is the ball bearing component that separates and positions the balls at equal intervals around the bearing's raceway. It is also referred to as the retainer or separator. The two standard cage designs include:

In addition to these standard cages, NHBB offers many other retainer designs to meet specific requirements. When selecting the most appropriate retainer for your application, some factors to consider include:

Table of Cage and Separator Types

The most common bearing cages are shown below. In some cases, such as in high-load applications, a full complement design may be the best choice. NHBB can also supply specially designed cages to meet your specific requirements. Please contact NHBB for assistance with optimum cage selection.

Cage Types

DESCRIPTION + DESIGN MATERIAL MAX SPEED (Ref.) dN** MAX. OPERATING TEMP.* COMMENTS TYPICAL APPLICATIONS
Ribbon
Two-piece stamped, crimped
R A.I.S.I. 305 Steel 150,000 900 °F Superior starting torque, low cost General purpose
Crown
One-piece stamped
H A.I.S.I. 410 Steel 150,000 900 °F Higher speed capability than ribbon retainer, low cost General purpose
Crown
One-piece machined
KB


KC
Phenolic-paper base

Phenolic-linen base
1,200,000 250 °F High speed capability
Porous material
Vacuum impregnated with oil
Medical
Machine tools
High speed motors
Crown
One-piece machined
M5 Polyamide-imide 1,200,000 500 °F High speed capability
Requires lubrication
Fully autoclavable
Medical/Dental
High temperature
Crown
One-piece machined
Silver coated
SC Patented composite metal-polymer 1,200,000 500 °F High speed capability
Self-lubricating
Fully autoclavable
Medical/Dental
High temperature
Full type
One-piece machined
KN


KM
Phenolic-paper base

Phenolic-linen base
2,000,000 250 °F Ultra-high speed capability
Angular contact bearing only
Porous material
Vacuum impregnated with oil
Machine tool spindles
High speed motors
Full type
One-piece machined
M4 Polyamide-imide 2,000,000 500 °F Ultra-high speed capability
Angular contact bearing only
Requires lubrication
Fully autoclavable
Medical/Dental
High temperature
Full type
One-piece machined
Silver coated
SF Patented composite metal-polymer 2,200,000 500 °F Ultra-high speed capability
Angular contact bearing only
Requires lubrication
Fully autoclavable
Medical/Dental
High temperature
Crown/Full type T1 Meldin®






PGM
Consult Factory 500 °F






500 °F
575 °F
Pourous polyamide-imide material
Vacuum impregnated with oil




Self-lubricating
Low to medium speed





Low speed
Light load

Additional Ball Separator Designs

DESCRIPTION + DESIGN MATERIAL MAX SPEED (Ref.) dN** MAX. OPERATING TEMP.* COMMENTS TYPICAL APPLICATIONS
Toroid TT PTFE 5,000 450 °F Low torque
Low speed
Angular contact bearing only
Slow rotation Oscillating motion
Cryogenic
Slug SL PTFE 1,000 450 °F Low torque
Low speed
Gimbal assembly
Slow rotation
Low speed

+ Typical Part Number Designation
* Rings and balls are heat stabilized to 300 °F.
**dN is bore (in millimeters) x rpm.

Additional cage designs and materials available. Please consult with factory.

Standard Cages

Ribbon cage

Ribbon, Two-Piece, Stamped and Crimped: One of two standard designs for miniature and instrument ball bearings, the two-piece ribbon retainer includes a closed pocket design for good durability and loosely clinched tabs, which are favorable for starting torque. This retainer design is economical and readily available but is limited to lower speed applications.* Two-piece ribbon retainers are used in radial bearings.

crown cage

Crown, One-Piece, Stamped: The one-piece stamped crown retainer is manufactured from hardened stainless steel and has coined ball pockets, which provide a hard, smooth, low-friction contact surface to the balls. This design is very lightweight, smooth running, cost effective, and readily available. The one-piece stamped crown retainer is also used in radial bearings, but it has a slightly higher speed capability than the stamped ribbon design. For speeds exceeding the capabilities of this retainer, a machined retainer should be considered.*

Machined Cages

crown cage

Crown, One-Piece: For high speed applications, a machined crown retainer design is a more appropriate choice than the two standard designs (stamped ribbon and stamped crown). This retainer is suitable for radial bearings. It is manufactured from a variety of materials to meet specific application requirements, including paper and linen-based phenolics and polyamide-imide. Both phenolic materials can be vacuum impregnated with oil, allowing for better lubricity within the ball pockets. The polyamide-imide material is fully autoclavable, making it well suited for many medical and dental applications. Additionally, polyamide-imide contains a small amount of graphite and PTFE, which aids in lubricity properties. Its lubricity may be further enhanced by a patented silver coating.

full cage

Full Type, One-Piece: This retainer design is best suited for ultra-high speed applications. Its balanced, symmetrical design makes it stable at very high speeds. This retainer, which can only be utilized with angular contact bearings, is manufactured from a variety of materials to meet specific application requirements, including paper and linen-based phenolics and polyamide-imide. Both phenolic materials may be vacuum impregnated with oil, allowing for better lubricity within the ball pockets. The polyamide-imide material is fully autoclavable, making it well suited for many medical and dental applications. Additionally, polyamide-imide contains a small amount of graphite and PTFE, which aids in lubricity properties. Its lubricity may be further enhanced by a patented silver coating.

Alternative Machined Cage Materials

NHBB manufactures machined cages from the following materials (consult with factory for availability):

Molded Cages

In addition to the machined retainers listed, the NHBB Precision Division offers a limited variety of molded retainers. These may have a lower speed capability as compared to machined retainers mainly due to the fact that machined retainers can be held to tighter tolerances for critical dimensions.

Trademarks

Meldin® is a registered trademark of Saint-Gobain Performance Plastics Corporation.
Delrin® is a registered trademark of DuPont.