What Lubricant to Select: Oil or Grease ?

The decision between selecting an oil or grease for lubrication can be made only after carefully considering several factors.

When to lubricate with oil:

Oil is generally preferable in systems that consistently operate at high temperatures (over 200°F). Oil is preferable over grease, as one can install circulation systems to help cool the system units.

When to lubricate with grease:

Grease is generally preferable to oil lubrication in bearing applications that operate at moderate speeds in which temperatures are not excessively high.

The table below, which compares, helps us easily understand when to lubricate with oil and grease.

S.no	Use Oil when	Use Grease when
1	The temperature of the system is high.	The temperature is not more than 200°F.
2	The system operates at high speeds.	The system operates at low speeds.
3	Oil-tight seals are readily employed.	Unusual protection is required from the entrance of foreign matter.
4	The bearing type is not suitable for grease lubrication.	Simple bearing enclosures are desired.
5	The bearing is lubricated from a central supply used for other machine parts.	Operation for long periods without attention is desired.