These fittings are also known as hydraulic grease fittings.

Zinc-plated steel fittings have mild corrosion resistance.

Fittings with a check valve prevent grease from leaking when pressure causes backward flow. The valve stays closed when not in use to keep out dirt and other contaminants.

UNF and UNEF threads are similar to threads on a machine screw or bolt. They require a sealant, such as an O-ring, to minimize leakage.

For technical drawings and 3-D models, click on a part number.