What is a zerk fitting?

A zerk fitting is a small metal nipple or connector that is used to lubricate machinery or equipment. It is also known as a grease nipple or grease fitting. The zerk fitting is typically installed on moving parts such as bearings, joints, and hinges, and is used to inject lubricant (grease) into the equipment to reduce friction and wear. The fitting has a small hole in the center that allows the lubricant to pass through from the grease gun. It is named after its inventor, Oscar U. Zerk. Zerk fittings come in various sizes and styles and are commonly found in automotive, industrial, and agricultural equipment. Regular maintenance and lubrication through zerk fittings increase the lifespan of equipment and reduce the need for repairs.