Anvil 8700159257, Malleable Iron Pipe Fitting, Square Head Plug, 1/2" NPT Male, Black Finish Plug for closing and terminating the end of a pipe or fitting Male National Pipe Taper (NPT) threads for connecting to a female pipe or fitting Made from malleable iron for tensile strength NPT threads for creating tighter seals than straight threads Black finish for corrosion resistance in oil and gas applications