1-1/2 NPT tap drill size
1-47/64"
- Inches
- 1.7344
- Millimetres
- 44.05
- Threads per inch
- 11.5
Drill a 1-47/64" hole, then cut the 1-1/2 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.
1-1/2 NPT thread and hole sizes
| Thread | 1-1/2 NPT National Pipe Taper, 11.5 threads per inch |
|---|---|
| Tap drill, no reamer | 1-47/64" 1.7344 in, 44.05 mm |
| Pitch | 0.0870 in 2.209 mm |
Tools for this job
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