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 a 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.