Greases are semisolid lubricants that are thicker than oil, so they stay in place to keep moving components lubricated and provide a barrier against water and debris. They extend the life of equipment by reducing the wear and tear that occurs when metal rubs against metal. Lubricating greases consist of base oil, thickeners, and additives. Their consistency ranges from semi-fluid (similar to applesauce) to very firm (similar to frozen yogurt). They're used for medium-speed, moderate-temperature applications on conveyors, machine parts, automobile components (chassis, wheel bearings, and gears), ball bearings, and other moving parts.