2. Lubricating greases

A lubricating grease is a product with a semi-fluid consistency obtained by dispersing a thickening or gelling agent in a mineral or synthetic lubricating oil, and which may include various additives designed to give it special properties depending on the intended applications.

A frequently cited illustration of the structure of a metal soap grease is that of a liquid-soaked sponge. Although some soaps and other gelling agents naturally possess lubricating properties, it is the oil that performs the main lubricating function by exuding and feeding the oil film. Certain products consisting of a powdery solid dispersed in oil, generally referred to as lubricating pastes, are in practice considered to be greases.

Lubricating greases are used in preference to oils when the amount of heat to be removed from the mechanism to be lubricated is low...