Lubricant & Grease

A substance introduced to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move is called Lubricant. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. Typically lubricants contain 90% base oil most often petroleum fractions called mineral oils and less than 10% additives. Additives deliver reduced friction and wear, increased viscosity, improved viscosity index, resistance to corrosion and oxidation, aging or contamination, etc.

Grease is a semisolid lubricant and generally consists of a soap emulsified with mineral or vegetable oil. The characteristic feature of greases is that they possess a high initial viscosity, which thins upon the application of shear & drops to give the effect of an oil-lubricated bearing of approximately the same viscosity as the base oil used in the grease. Greases are applied to mechanisms that can only be lubricated infrequently and where lubricating oil would not stay in position. They also act as sealants to prevent ingress of water and incompressible materials. Grease-lubricated bearings have greater frictional characteristics due to their high viscosity.