Anvil 8700158754, Steel Pipe Fitting, Coupling, 1" NPT Female, Galvanized Finish Coupling for connecting two pipes going in the same direction Female National Pipe Taper (NPT) threads on both ends for connecting two male threaded pipes Made from steel for greater rust resistance than iron NPT threads for creating tighter seals than straight threads Meets specifications ASTM A53 and ASME B 1.20.1 for quality assurance