First of all, in the bearing bad bearing assembly hole size, shape accuracy, the bearings will be affected, can not play the best performance. For example, with the parts bearing hole dimensional accuracy and shape accuracy is poor caused by the deformation of the bearing outer ring, resulting in deterioration of the roundness bearing; the accuracy of the shoulder block, will have a bearing outer ring, roller tilt increased focus load bearing fatigue life decreased, more serious cause of cage damage, sintering;  bearing inner ring of the spindle pole bearing the accuracy of the file is not good, such as size, roundness, cylindrical, corrugated aspects of the roughness, location, degree of accuracy will obviously lead to the increase in the value of the entire spindle vibration.
Second, the sets of bearings in the assembly before the strict precision matching, so  before use, the scattered parts of the bearing without re-measurement matching is not interchangeable use.
Third, clean of the spindle bearings and spindle feet. As the compact ingot feet, the ingots foot cavity there are many other parts, their cleanliness also affect the cleanliness of the bearing cavity. Therefore, the foot part of the assembly before using the ingot pre-cleaning, assembly assembly later, and then the assembly spindles feet, including bearing fine cleaning process is a more reasonable process.
Fourth, the bearing assembly should not be subject to the bump and shock, bump and shock 

Other News:
The proper use of the spindle bearing
The trap and the control valves difference
The installation of bearings
The rolling bearing knowledge
Ceramic ball bearing choice and the matters need attention
Engine block main bearing failure and repair methods
The gear pump housing hole processing method
The rolling bearing installation and coordination