Graphite is a

A lubricant is a substance, which reduces friction between mating parts. Lubricants are grouped into three categories.

1. Liquid lubricants: Some of the most commonly used liquid lubricants are mineral oil, fatty or vegetable oils, synthetic oils.
2. Semi-liquid lubricants: Greases are most commonly used lubricants with a higher viscosity than oils. These are employed for slow speed and heavy pressure operations like drawing, rolling and extrusion processes.
3. Solid lubricants: Graphite is the commonly used solid lubricant. Other types of solid lubricants are soapstone, talc, French chalk etc.