Thickener families
Lithium, lithium complex, calcium sulfonate complex, and polyurea each offer different balances of heat resistance, water resistance, mechanical stability, and compatibility.
Base oil and additives matter too
Two greases with the same thickener and NLGI grade can perform differently because of base-oil viscosity, synthetic or mineral oil, EP chemistry, corrosion inhibitors, and oxidation stability.
A reliable selection sequence
Define speed, load, temperature, water, dust, application method, and relubrication interval. Then screen thickener, base-oil viscosity, NLGI grade, and compatibility.