superwhole 1/2" male x 1/2" male hex nipple stainless steel 304 threaded pipe fitting npt dan speed the dan speed nipple is a stainless steel 304 pipe fitting with male national pipe taper (npt) threads for connecting and extending female threaded pipes. the fitting has npt threads for creating tighter seals than straight threads. it can be applied in: hydrant pipe, air compressor, laundry faucet, extended shower-head and hose, natural gas line and irrigation applications, etc.