Quote Originally Posted by JAZZCNC View Post
BK is Fixed end and consists of of 2 angular contact bearings held within the housing. The photo shows all sizes depending on end machining and screw diameter. IE: Bk12 being used for 16mm screws Bk15 20mm etc.

BF is the floating end and just uses normal bearing which floats within the housing and is held onto the ballscrew with a Circlip.
That's just what i thought until i took the BF12 apart and found 2x 6001z bearings !!!