Pipe Tap Drill Sizes
| TAPER PIPE – NPT |
STRAIGHT PIPE – NPS |
|||
| TAP | DRILL | TAP | DRILL | |
| SIZE | SIZE | SIZE | SIZE | |
| 1/8-27 | R | 1/8-27 | S | |
| 1/4-18 | 7/16 | 1/4-18 | 29/64 | |
| 3/8-18 | 37/64 | 3/8-18 | 19/32 | |
| 1/2-14 | 23/32 | 1/2-14 | 47/64 | |
| 3/4-14 | 59/64 | 3/4-14 | 15/16 | |
| 1″-11-1/2 | 1-5/32 | 1″-11-1/2 | 1-3/16 | |
| 1-1/4-11-1/2 | 1-1/2 | 1-1/4-11-1/2 | 1-33/64 | |
| 1-1/2-11-1/2 | 1-47/64 | 1-1/2-11-1/2 | 1-3/4 | |
| 2″-11-1/2 | 2-7/32 | 2″-11-1/2 | 2-7/3 | |
| 2-1/2-8 | 2-5/8 | 2-1/2-8 | 2-21/32 | |
| 3″-8 | 3-1/4 | 3″-8 | 3-9/32 | |
| 3-1/2-8 | 3-3/4 | 3-1/2-8 | 3-25/32 | |
| 4″-8 | 4-1/4 | 4″-8 | 4-9/32 | |