Contamination is avoided by installing bearings in a clean environment. While a clean room or laminar flow
workbench is recommended, these are not essential for normal applications as long as basic precautions are used.

• Avoid handling bearings with bare hands. Use talc-free finger cots or surgical gloves. This is particularly important to avoid corrosion of 52100 chrome steel bearings.
• Work areas and benches should be cleaned daily to avoid dust build up.
• Keep bearings in original packaging until used. Never leave bearings exposed to the environment.
• Work tools must be kept clean and burr-free
• It is preferable that assembly workers wear clean external clothing (caps, smocks, shoe-covers) that meets clean-room specifications. No make-up or cosmetic powder.
• Mating components should be cleaned prior to use. Be careful in the choice of cleaning materials as regular cotton swabs and cleaning cloths may add contamination from lint. Use specific lint-free clean room products.

The most common cause of small bearing failure is excessive force applied during assembly, which usually results in the following adverse effects on bearing performance:

Excessive forces during assembly of small bearings are generated by poor handling techniques or incorrect/uncontrolled interference due to poor design or tolerance stack up.

• Follow all guidelines for mounting practices. Make sure that fixtures are aligned.
• Bearings are susceptible to shock or impact loads, especially when the axial play has been removed
  through preload. Dropping a preloaded assembly, or even placing it on a hard surface, can cause
  brinelling. It is recommended that assembly work surfaces are covered with a layer of shock-absorbing material.

Bearings are susceptible to corrosion and should be kept in a dry environment. The lubricant in a bearing will provide some measure of corrosion resistance to the internal raceways, but the acid from skin can corrode the outer surfaces. 52100 chrome steel bearings will quickly corrode if the lubricant is cleaned out, so bearings made from this material should never be used “dry”.

Bearing Misalignment

Must be < θf (page 13)

• Locating shoulders on mating components must be parallel to bearing raceway faces.
• Shaft and housing bores must be concentric. This is particularly true when more than 2 bearings share a common component. For example, if a third bearing is added to the above arrangement, the resulting assembly has almost no tolerance for misalignment of the bearing outer ring.