JIC 37* flare fittings are a zinc plated steel fitting with a 37* flared end which creates a sealed connection usually used in hydraulic fluid applications. Male straight fittings feature a flared tube end and a male pipe thread end for threading into internally threaded mating parts. They come in either the same size tube/pipe thread or alternating sizes depending on the application. These fittings can withstand up to 3,000 PSI of pressure. The Boss O'Ring provides built in added sealing power.