The ball bearing cage(also know as bearing retainer or bearing separator) is the component in a ball bearing. There are four basic types of cages that are the most common, they are J type(two-piece steel ribbon), W type(one-piece steel crown), RJ type(two-piece steel rivet), TW type(one-piece nylon crown).
J type: two-piece steel ribbon
lower torque
ball guided
material can be carbon steel, stainless steel
W type: one-piece steel crown
low torque
low to medium speed
inner ring guided
material can be carbon steel, stainless steel
RJ type: two-piece steel rivet
suitable for ball bearing with over 10mm bore
high load
ball guided
material can be carbon steel, stainless steel
TW type: one-piece nylon crown
high speed, low noise
ball guided
TA/TB type: one-piece full machined
used in angular contact ball bearings
TA is outer ring guided; TB is inner ring guided.
material is phenolic resin