Lubrication plays a vital role in the performance and life of rolling element bearings. A bearing lubricant that is designed for specific operating conditions will provide a load bearing wear protective film. The ideal condition is when the friction surfaces are separated by this film. In addition to providing this load bearing film, the lubricant should also allow for the dissipation of frictional heat thus preventing overheating of the bearing and deterioration of the lubricant and provide protection from corrosion, moisture, and the ingress of contaminants.

However, frequently bearings come from the factory with a lubricant other than desired. In the interest of time, availability, and the assurance of suitable product, often bearing relubrication (re-lube) is the most cost effective solution. Furthermore, lubricants sometimes will breakdown before the bearings themselves. It is also economical at times to relubricate a bearing rather than to scrap it.