Sliding contact bearings can be CLASSIFIED on the basis of the thickness of the lubricating AGENT layer between the bearing and the JOURNAL. They can be classified as follows:

• Thick film bearings: These type of bearings have their working SURFACE separated by a layer of the lubricant. They are also known as hydrodynamic lubricated bearings.
• Thin film bearings: In this type of bearings the surfaces are partially in direct contact with each other even after the presence of a lubricant. The other name for such type of bearings is boundary lubricated bearings.
• Zero Film Bearings: These type of bearings as their name suggests have no lubricant present between the contact layers.
• Externally or hydrostatically pressurized lubricated bearings: These bearings are able to without any relative motion SUPPORT steady loads.

Sliding contact bearings can be classified on the basis of the thickness of the lubricating agent layer between the bearing and the journal. They can be classified as follows: