Small dirt particles such as grit and dust that get into the bearing or lubricant will cause excessive wear. Causes that may introduce dirt can be:

Wrong type of seal:If the seal is not able to withstand certain conditions, such as high speed, temperature, or loads, it may fail and no longer prevent dirt entering the bearing.

Incorrect positioning of seal: If a seal is not installed correctly, the bearing may not be sealed properly, and dirt particles may enter the system.

Worn or damaged seal: The performance of a seal can be reduced over time due to wear or damages. A worn or broken seal offers no protection against contaminations.

Incorrect storage or usage: Bearings must be stored in a clean, cool area where they are not exposed to moisture and dust or other dirt. Do not remove the packaging and protective film until right before assembly. Caution is also required during transportation and moving of bearings. Impacts and falls can cause damage that is not always visible, which may increase the chances of contamination.