Grease Fittings
Grease fittings (also known as Zerk fittings or grease nipples) are lubrication points permanently fitted on mechanical systems and bearings to feed lubricants to the systems or bearings without overflowing or leaking. The fittings remain closed to keep impurities out until they are forced open by the pressure from a grease gun, allowing grease to flow to the system or bearing.