Because in the case of single-row taper roller bearings, loads can be transferred from one track to the other, skewed to the bearing axis, a force effective in the axial direction is present under radial load and must be equalized by an external opposing force
The main dimensions correspond with the specifications in DIN 616:2000, DIN-ISO 355 and DIN 720:1979
The suffixes are explained in the following:
J: Window cage made of steel plate. An appended character identifies the cage design
Q: Optimized contact geometry and surface properties