The cage material is extremely thin, somewhere between 20 and 40k I think. In my case, the barrel was not inserted into the hole, but used as a roller on another surface. After about 2 days of rolling this race at about 200 rpm, stress cracks developed throughout the race and fell apart within hours of the crack. I think it would be a great bearing if a suitable round bore was used in it, but its race is not thick enough for my particular application.