A lubricant in which base oil, typically 70 to 95 percent of the mass, is trapped in a fibrous or particle thickener so it stays where plain oil would run out. Under shear and heat the thickener releases oil to the contact; at rest it holds the oil in place and helps seal out dirt and water. Greases are specified by thickener type, base oil viscosity, NLGI grade and additives, and most rolling bearings in a plant run on them.
That grease is an EP2 lithium complex on a 220 base oil, fine for the fan bearings.
Base oil viscosity matters more than the grease name. A grease on a 100 cSt base and one on a 460 base can both be sold as general purpose NLGI 2.
Also heard as
- lubricating grease
Related terms
Thickener
Solid structure in a grease, usually a metal soap or polyurea, that holds the base oil like a sponge.
NLGI grade
Number from 000 to 6 describing grease stiffness, based on cone penetration after working.
Bleed
Separation of oil from a grease, either as a storage problem or as the intended release of oil to a bearing.
Grease compatibility
Whether two greases can be mixed without losing consistency, dropping point or stability.
Lithium complex
Grease thickener made from a lithium soap plus a complexing acid, the all-purpose bearing workhorse.