【NPT THREADS】: American National Pipe Taper (NPT) threads, 1/4" x 1/4" NPT female pipe (6 pack), 1/4" x 1/4" NPT male pipe (6 pack)【PREMIUM MATERIAL】: High quality solid brass, firm and durable, providing high resistance to abrasion and corrosion【DURABLE】: These fittings are not cast products and has thick wall, providing a longer service life, solid brass can withstand up to 100 °C (212 °F)【SUPERIOR THREADS】: Deeper threads design allows the fittings to be better engaged with the object to enhance fixation, and the smoother threads make installation easier and faster【FUNCTION】: Male and female National Pipe Taper (NPT) threads for connecting two pipes, and can be used to connect various pipes, such as air pipe, fuel pipe, water pipe as well as air tools American National Pipe Taper (NPT) threads American National Standard Pipe Thread standards, often called national pipe thread standards for short, are U.S. national technical standards for screw threads used on threaded pipes and pipe fittings. They are tapered thread series for various purposes including rigidity, pressure-tight sealing, or both. Firm: Heavy duty solid brass has strong corrosion resistance, thicker wall extends the service time, and brass pipe fittings are durable than iron and iron galvanized pipe fittings. Great fixation: Deeper and smoother threads allow better bite, enhancing fixation, not easy to slip. Tips: For better sealing, we suggest that all fittings must be used with sealing tape. These fittings are not allowed by federal law to be installed for potable water use in the U.S.A. and its territories. Contents: 6 pack of 1/4" x 1/4" NPT female pipe 6 pack of 1/4" x 1/4" NPT male pipe