1 NPT tap drill size
1-5/32"
- Inches
- 1.1562
- Millimetres
- 29.37
- Threads per inch
- 11.5
Drill a 1-5/32" hole, then cut the 1 NPT thread with a taper pipe tap. This is the size for drilling and tapping with no reamer step.
Charts differ on pipe threads. Some list a smaller drill because they assume the hole is taper-reamed first. If you ream, use the drill size your tap or reamer maker lists.
1 NPT thread and hole sizes
| Thread | 1 NPT National Pipe Taper, 11.5 threads per inch |
|---|---|
| Tap drill, no reamer | 1-5/32" 1.1562 in, 29.37 mm |
| Pitch | 0.0870 in 2.209 mm |
Tools for this job
As an Amazon Associate we earn from qualifying purchases. Details