Drillco nominal size of a taper pipe tap (NPT) is that of the pipe fitting to be tapped, not the actual size of the tap. Carbon steel taps are used to rethread damaged or jammed threads, or to thread mild steels. They can be used for either through or blind holes. Uncoated tools feature just the base substrate without any additional treatment or coatings and are suitable for a wide range of applications. Comes with round with square end shank. Straight flute tools allow chips to collect in the flutes as they cut and are well suited for most applications in shallow cuts. Right-hand cut tools have a cutting action that engages when they are run in a clockwise direction.