When choosing the ABEC grade, the factors to be considered are: radial and axial runout requirements; bore and O.D. fits; and audible noise level. The table shows the bore and O.D. size tolerances and the radial runout limits for each ABEC grade. Grades 5 and 7 are preferred for most standard applications.

The Dimension Control charts provide a complete description of the tolerances controlled by the ABEC level. Normally, race finish and race geometry are superior in ABEC 5P and higher. NHBB recommends these grades for precision assemblies where low noise (mechanical or audible), minimal runout and long life are important considerations for noise sensitive applications.

*ABEC 1 miniature and instrument bearings of both the metric and inch configurations meet the tolerances of ABMA Standard 20 for ABEC 1 metric series bearings.