Lubricating greases and their functions

Lubricating greases are semi-solid lubricants made by thickening a lubricating oil (mineral oil) with a metallic soap (Ca, Na or Li soap of fatty acids). Examples: calcium (cup) grease, sodium (fibre) grease, lithium grease. They are used where liquid oil cannot stay in place, for example in slow-moving, heavily loaded or intermittently working bearings, open gears, chassis and axles, and in machines that cannot be lubricated regularly.

Functions of greases

1. Reduce friction and wear between surfaces moving slowly under heavy load.
2. Act as a seal that keeps out dust, dirt and water.
3. Stay in place and need less frequent refilling, so they suit hard-to-reach parts.
4. Protect metal from corrosion.
5. Absorb shock and reduce noise.