Anvil 8700163507, Malleable Iron Pipe Fitting, Union, 1" NPT Female, Galvanized Finish Union pipe fitting for joining two pipes Female National Pipe Taper (NPT) threads on both ends for connecting to male pipes Made from malleable iron for tensile strength National Pipe Taper (NPT) threads for creating tighter seals than straight threads Galvanized finish resists rust in water, air, and steam applications