This standard specifies boundary dimensions and tolerances for ball bearings with spherical outside surfaces and extended inner ring width. The feature of mating housing and bearing spherical surfaces is intended to provide initial self-alignment at mounting. Included are pillow block, flanged and take-up unit housings.

The housings in this standard are commonly made from ferrous materials. Those shown in tables 1, 2, 3 and 4 are generally cast, whereas those shown in tables 5, 6 and 7 are generally pressed.

Relubrication features are optional and may be designed to interface with the lubrication holes of mating bearings covered by ANSI/ABMA Standard 15, Ball Bearings with Spherical Outside Surfaces and Extended Inner Ring Width (Includes Eccentric Locking Collars), so that bearings may be properly relubricated. This standard does not include the design or dimensions of relubrication features.