Many myths and misconceptions exist about what grease is, what it’s used for and how it works.
You’re no doubt familiar with oil lubricants like hydraulic oils, turbine oils, gear oils and so forth. They have one thing in common; they are composed of base oil(s) and performance additives. The oil keeps the moving surfaces separated and the additives improve protection from wear, seizure, rust, and many other detrimental factors.
How is grease different? It’s like an oil lubricant but adds a third component called a thickener. The thickener is a semi-soluble material, which when dispersed uniformly in the oil, provides body and structure to the lubricant. The oil (and additives) do most of the lubricating and the thickener keeps the lubricant in place. That is what grease is all about – staying in place. An oil does a great job at lubricating and removing heat, but requires a closed system, which may include a pump, filter, heat exchanger or other equipment.
Due to their inherent lubricating abilities, greases lubricate around 90% of all rolling element bearings!