The gelling agent that makes up roughly 5 to 30 percent of a grease and gives it body. Soap thickeners are made by reacting a fatty acid with a metal hydroxide such as lithium, calcium, sodium or aluminum, and complex soaps add a second acid for higher temperature service. Non-soap thickeners include polyurea, clay and silica. Thickener type largely sets dropping point, water resistance and compatibility, so it is the first thing a lube tech checks before mixing products.
Check the thickener before you load that gun, this line was on polyurea and the new tube is lithium.
Also heard as
- gellant
Related terms
Grease
Semi-solid lubricant made of oil held in a thickener sponge, usually with additives.
Lithium complex
Grease thickener made from a lithium soap plus a complexing acid, the all-purpose bearing workhorse.
Polyurea
Non-soap grease thickener with long high-temperature life, standard in sealed electric motor bearings.
Calcium sulfonate
Grease thickener based on overbased calcium sulfonate, known for water resistance and built-in EP protection.
Grease compatibility
Whether two greases can be mixed without losing consistency, dropping point or stability.