3/4 - 14 NPT 12" Long Tape, 5 FLUTE TAP - 5 flute Could not find markings on this, but compared it to other taps and it appears to be NPT This is 12" Long Tap Deep Tap Long Reach Tap I have had these taps for over 20 years, I never used them, but they may have been used. This tap is in real good condition BIN 151