Lubricants: Types and Properties of Lubricants - Mechanical Education

Lubricant oils:

Lubricant: In this article we will discuss about what is lubricant, types of lubricants like liquid lubricant, semi-liquid lubricant, solid lubricant and properties of lubricant. The lubricant is a medium or a substance which has uniform properties used to reduce friction in between bearings, moving parts etc. and lubricants used to carry away the heat generated by friction. this substance is also used to protect from corrosion. Lubricants are only the most used medium to work free in between moving parts and reducing the heat produced in between the parts there are three types of lubricants are in usage, according to the work required a different type of lubricants are used.

Types of Lubricant oil's:

There are different types of Lubricant Oils they are as follows:

• Liquids  
• Semi-Liquid  
• Solid

Liquid lubricants:

The liquid lubricants usually used in small rotational bearings and parts which is up to 500 R.P.M this type of lubricants are mineral oils and synthetic oils. Mineral oils are mostly used due to less cost and more stability than synthetic oils.

Semi-Liquid lubricants:

This type of lubricants is mostly used when the speed of journal is about 500-1500 R.P.M. this type of oils has high viscosity than liquids

Eg: Grease

Solid lubricants:

Solid lubricants are mostly used when the speed of the journal is more than 1500 R.P.M.

Eg: Most commonly used solid lubricants is graphite.

Properties of Lubricants:

The following are the properties of Lubricants: 

• Viscosity
• Density
• Flash point

Fire point: This is the last point that lubricant can withstand out of the burning.
Oiliness: Oiliness is the quality measurement of lubricating.
Viscosity Index: This is used to denote the degree of variation of viscosity with respect to temperature.
Freezing point: It indicates the temperature at which the oil ceases to flow when cooled.