ITEM NAME:NPT1/4-18 High Speed Steel Taper Pipe Tap Thread 1/4'' Metalworking Tool J,a.1x 1/4" - 18 NPT HSS Taper Pipe Tap. Using High-quality steel, high hardness quenching rigid and long service life; sharp cutting performance, good chip effect; good surface finish, large chip flutes, removal chip smooth.