| Nominal Dia. |
Major Dia. |
Major Dia. |
Tapping Drill Size |
TPI | Pitch |
|---|---|---|---|---|---|
| #0-80 | 0.060 | 3/64 | .046875 | 80 | 0.317 |
| #1-72 | 0.073 | #53 | .0595 | 72 | 0.353 |
| #2-64 | 0.086 | #50 | .07 | 64 | 0.397 |
| #3-56 | 0.099 | #45 | .082 | 56 | 0.453 |
| #4-48 | 0.112 | #42 | .0935 | 48 | 0.529 |
| #5-44 | 0.125 | #37 | .104 | 44 | 0.577 |
| #6-40 | 0.138 | #33 | .113 | 40 | 0.635 |
| #8-36 | 0.164 | #29 | .136 | 36 | 0.705 |
| #10-32 | 0.190 | #21 | .159 | 32 | 0.794 |
| #12-28 | 0.216 | #15 | .18 | 28 | 0.907 |
| 1/4”-28 | 0.250 | #3 | .213 | 28 | 0.907 |
| 5/16”-24 | 0.313 | I | .272 | 24 | 1.058 |
| 3/8”-24 | 0.375 | Q | .332 | 24 | 1.058 |
| 7/16”-20 | 0.438 | 25/64 | .390625 | 20 | 1.270 |
| 1/2”-20 | 0.500 | 29/64 | .453125 | 20 | 1.270 |
| 9/16”-18 | 0.563 | 33/64 | .515625 | 18 | 1.411 |
| 5/8”-18 | 0.625 | 37/64 | .5625 | 18 | 1.411 |
| 3/4”-16 | 0.750 | 11/16 | .6875 | 16 | 1.587 |
| 7/8”-14 | 0.875 | 13/16 | .8125 | 14 | 1.814 |
| 1”-12 | 1.000 | 15/16 | .90625 | 12 | 2.117 |
| 1-1/8”-12 | 1.125 | 1-3/64 | 1.046875 | 12 | 2.117 |
| 1-1/4”-12 | 1.250 | 1-11/64 | 1.171875 | 12 | 2.117 |
| 1-3/8”-12 | 1.375 | 1-19/64 | 1.296875 | 12 | 2.117 |
| 1-1/2”-12 | 1.500 | 1-27/64 | 1.421875 | 12 | 2.117 |