Major Functions of Lubricating Oils
February 24, 2017Definitions of Some Physical Characteristics of Lubricants
February 24, 2017Definitions of Some Physical Characteristics of Lubricants
This notion refers to the resistance of oil against flowing. It results from internal frictions of molecules. By changing oil temperature, its viscosity will change. Warmer oil signifies lower viscosity. Usually, viscosity is measured at 40 and 100°C.
Definitions of Some Physical Characteristics of Lubricants
Definitions of Some Physical Characteristics of Lubricants
1-Viscosity
This notion refers to the resistance of oil against flowing. It results from internal frictions of molecules. By changing oil temperature, its viscosity will change. Warmer oil signifies lower viscosity. Usually, viscosity is measured at 40 and 100°C.
2-Viscosity Index
It is a factor which reveals the effects of temperature change on viscosity. Higher viscosity index implied that changes in viscosity of the oil due to temperature variations reduce and vice versa.
3-Pour Point
The lowest temperature in which oil still can flow.
4-Flash Point
Flash point is the lowest temperature in which oil has sufficiently turned into vapor so that it burns in a moment and then turns off. This physical characteristic is an indicator for measuring the level of combustibility and volatility of oil.
5-Fire Point
Fire point is the least temperature in which oil produces so much air that in adjacency of fire it might combust. The combustion continues for a while. Usually, combustion point is almost 15 points above fire point. It is not usually measured and mentioned.
6-Density
Density denotes the mass of a cubic centimeter of oil at 15.6°C (kg/m3 or g/cm3). This characteristic is used to determine the type of basic oil (organic or synthetic), conversion of weight to volume and vice versa.
Major Functions of Lubricating Oils