The model RA is compact that reduces the thickness of the inner and outer ring to the lowest level. With the division in the outer ring-like model RB, the model RA is suitable for a position where the lightweight, compact style and the high-precision rotation in the inner ring are needed, such as the rotating part in a mechanical watch.
HRA series is a kind of small size and light weight cross roller bearing which the wall thickness is thinner. it is small and can with stand heavy load. So bearing housing and presser flange can be light wight. It can be suited for the hand location of the robots used in the rotary location.