Tolerance of a Bearing
TOLERANCES You will find interesting to note that so as to get bearing 'Perfect'. The scientists have now succeeded in space in their sky-lab 1st mission (ie. in 0 gravity) by the help of Astronauts.
The term bearing tolerances refers to the very close dimensional limits of bore, outside diameter and width of a bearing.
Tolerances of boundary dimension are internationally standardized and are maintained in order to ensure accurate mounting of the bearing on the shaft and in the housing; these tolerances also ensure precise operations of the equipment in which the bearings are used.
One main factor must be noted that average dimension of any standard bearings are always on Minus side. This means that if you take the measurement of bore, outside diameter or width of any kind of bearings, then it should be measured from eight different points and the average of all the eight reading will always be on Minus side.