Miniature ball bearings
Miniature ball bearings are special roller bearings in small geometric dimensions. Experts use the term miniature ball bearings up to a bore diameter of 10 mm.
A further feature of miniature ball bearings is the designation system which often uses only three instead of four digits.
In terms of their design, most miniature ball bearings are deep groove ball bearings and cover metric (ISO) and imperial (ANSI/AFBMA) dimensions.
Sometimes there is an additional flange (stop) mounted on one side of the outer race to make mounting easier.