THE ESSENTIAL FUNCTION OF ANY LUBRICANT is to prolong the life and increase the efficiency of mechanical devices by reducing friction and wear. Secondary functions include the dissipation of heat, protection from corrosion, power transmission, and removal of contaminants. Generally, fluid lubricants are difficult to retain at the point of application and must be replenished frequently. If, however, a fluid lubricant is thickened, its retention is improved, and lubrication intervals can be extended. A lubricating grease is simply a lubricating fluid that has been gelled with a thickening agent so that the lubricant can be retained more readily in the required area.