· Surface zinc or phosphate plated – limited rust resistance.

· Relatively large clearance between rolling elements and pockets – can cause noise and friction.

· At high speed, centrifugal force may cause deformation or fracture.

· Load: centrifugal and inertial forces can be calculated using bearing dynamics, but stiffness scatter of pressed parts makes results uncertain.

· Speed: limiting speed from bearing catalogues can be used, but individual cage fatigue life cannot be accurately calculated.

· Life: no standard cage life model – usually assumed same as calculated bearing life (in reality often shorter).