N7 Union Nut is a type of threaded fitting used in various applications such as plumbing, fluid handling systems, and HVAC systems. It is designed to connect two pipes or tubes together by screwing the nut onto the threaded end of one pipe and tightening it against the face of a mating surface of the other pipe to form a secure, watertight seal. Apart from that, N7 Union Nut is made of brass or stainless steel, which makes it resistant to rust and corrosion. It also features a hexagonal shape that allows for easy tightening with a wrench or pliers.