Installationof HELI-COIL® Pipe Thread Inserts for NPT and ANPT Standard shop practice is followed. Variations in material, drills and drilling equipment may make larger or smaller drills necessary to produce acceptable threads. Drill to depth given in Col. 3 or 4. Use standard reaming procedure. Forexample, if you have a 1/8” NPT pipe tap, the R type is the appropriate drill bit to use with this tap. If the pipe tap is tapered, the ideal drill size is 21/64mm in fraction form or 0.339”. For non-tapered or straight pipe taps, use a drill size of 11/32mm or 0.344”. This delivers 27 threads per inch. Vay Tiền Cấp Tốc Online Cmnd.

3 8 npt thread drill size