Angular contact ball bearings are constructed such that their races and the bearing balls contact points are at some angle relative to the axis of the operating axis of the bearing. Standard operating angles are 15,30, and 40 degrees.Angular bearings are available in standard imperial (inch) and metric (mm) sizes

Angular contact bearings are assembled with a preload, which is applied between the inner race, the bearing ball and the outer races. The preload minimizes or removes gaps between the bearing balls and the inner and outer races. Angular contact bearings may operate with heavy thrust loads and moderate radial loads. Angular contact ball bearings are a classifications as single row. Radial ball bearings, radial ball bearings. NTN’s designations for the various contact angles are:

“C”=15

No Designation = 30

“D” = 40