Types of Lubricant: Lubricant is a material which circulates through the lubrication network to provide lubrication at various points. Lubricants are classified in three forms: Fluid oils, semi solid and solids.
Fluid Oil
These are liquid oils and used in engine lubrication system.
Semi Solids
Such as Grease. These types of lubricant are used in chassis lubrication system.
Solid
Such as graphite and mica. Such types of lubricant are used in journal bearing and springs with some fluid oils.
Fluid oils can also be classified according to their sources - as animal, vegetable, and mineral oil. Mineral oils are used for lubricating automotive engines because they have most of the desired qualities and simultaneously they are available easily and cheap. The function of a lubricant is to decrease friction by preventing direct contact of rubbing surfaces. It makes a layer between adjacent surfaces. The ability to keep two surfaces apart depends on its various properties.