Lubricating Oils

Lubricating oils reduces friction and wear between two sliding metallic surfaces by providing a continuous film between them. The lubricants also serve like as coolant, corrosion preventer and sealing agent.

Good lubricating oil must have a low vapour pressure (or high boiling point) and low freezing point. It must be stable at high temperature, should not oxidize or cause corrosion. Above all a lubricant is required to be adequately viscous for particular application.

Mineral oils blended with vegetable oil are used in practice. Synthetic lubricating oils are now being manufactured to have molecular structure resulting in desired properties, particularly under severe operating conditions. The lubricants are further explained below.