The Angular Bearings Engineers Committee (ABEC) set up tolerance grades for bearings. These classes or grades of bearings allow common language or standards in bearing design.
The ABEC tolerances get more precise as the category number gets higher. For example ABEC 3 is a more precise bearing then ABEC 1. RBI Bearing supplies bearings in both ABEC 1 and ABEC 3. More information on RBI Bearing’s Radial Ball Bearing Tolerances can be found here in the following chart.