Eaton Aeroquip 2216-8-10S Steel Pipe Fitting, Adapter, 1/2" NPT Female x 5/8" Male Straight Thread O-Ring (Pack of 4) National Pipe Thread (NPT) female adapter to connect a pipe to an NPT male thread NPT female threads at both ends for connecting two pipes Steel for weldability and greater resistance to rust than iron Standard duty for light to medium pressure applications Society of Automotive Engineers (SAE)-compliant for SAE standards J512, J513, J514, J1926 and J1453 for functional requirements