Single row angular contact bearings are designed to accommodate  axial loads acting in one direction only, they commonly have a 40 degree contact angle and there fore support heavy axial loads. They are non separable bearings.

The basic design single row angular contact bearing are intended for arrangements where only one bearing is used at each bearing position, they have normal tolerances concerning width and are therefore not suitable for mounting directly adjacent to each other.

Matched pairs or sets of these bearings are manufactured for bearings that need to be mounted immediately adjacent to each other. So that a given internal clearance or preload and/or an even load distribution can be obtained without the use of shims.

More commonly now fitted in a wide range of metric sizes. However imperial sizes are still available.