Tap drill size finder
Pick a thread and get the drill to use before tapping. Every inch size shows the % of thread you'll get, so you can trade a little strength for easier tapping when you need to.
Most-used tap drill sizes
| Thread | Tap drill | Decimal | mm |
|---|---|---|---|
| #4-40 | #43 | .0890 in | 2.26 |
| #6-32 | #36 | .1065 in | 2.71 |
| #8-32 | #29 | .1360 in | 3.45 |
| #10-24 | #25 | .1495 in | 3.80 |
| #10-32 | #21 | .1590 in | 4.04 |
| 1/4-20 | #7 | .2010 in | 5.11 |
| 5/16-18 | F | .2570 in | 6.53 |
| 3/8-16 | 5/16 | .3125 in | 7.94 |
| 1/2-13 | 27/64 | .4219 in | 10.72 |
| M3 x 0.5 | 2.5 mm | .0984 in | 2.50 |
| M4 x 0.7 | 3.3 mm | .1299 in | 3.30 |
| M5 x 0.8 | 4.2 mm | .1654 in | 4.20 |
| M6 x 1 | 5 mm | .1969 in | 5.00 |
| M8 x 1.25 | 6.8 mm | .2677 in | 6.80 |
| M10 x 1.5 | 8.5 mm | .3346 in | 8.50 |
| M12 x 1.75 | 10.2 mm | .4016 in | 10.20 |
Charts
- Inch tap drill chart (UNC/UNF)
- Metric tap drill chart
- Drill size chart: number, letter, fraction
- Fraction to decimal to mm chart
- Metric clearance hole chart
- What % of thread means
- How to tap a hole
All thread sizes
Inch (Unified)
- #0-80 UNF tap drill
- #1-64 UNC tap drill
- #1-72 UNF tap drill
- #2-56 UNC tap drill
- #2-64 UNF tap drill
- #3-48 UNC tap drill
- #3-56 UNF tap drill
- #4-40 UNC tap drill
- #4-48 UNF tap drill
- #5-40 UNC tap drill
- #5-44 UNF tap drill
- #6-32 UNC tap drill
- #6-40 UNF tap drill
- #8-32 UNC tap drill
- #8-36 UNF tap drill
- #10-24 UNC tap drill
- #10-32 UNF tap drill
- #12-24 UNC tap drill
- #12-28 UNF tap drill
- 1/4-20 UNC tap drill
- 1/4-28 UNF tap drill
- 5/16-18 UNC tap drill
- 5/16-24 UNF tap drill
- 3/8-16 UNC tap drill
- 3/8-24 UNF tap drill
- 7/16-14 UNC tap drill
- 7/16-20 UNF tap drill
- 1/2-13 UNC tap drill
- 1/2-20 UNF tap drill
- 9/16-12 UNC tap drill
- 9/16-18 UNF tap drill
- 5/8-11 UNC tap drill
- 5/8-18 UNF tap drill
- 3/4-10 UNC tap drill
- 3/4-16 UNF tap drill
- 7/8-9 UNC tap drill
- 7/8-14 UNF tap drill
- 1-8 UNC tap drill
- 1-12 UNF tap drill
Metric (ISO)
- M1.6 x 0.35 tap drill
- M2 x 0.4 tap drill
- M2.5 x 0.45 tap drill
- M3 x 0.5 tap drill
- M3.5 x 0.6 tap drill
- M4 x 0.7 tap drill
- M5 x 0.8 tap drill
- M6 x 1 tap drill
- M8 x 1.25 tap drill
- M10 x 1.5 tap drill
- M12 x 1.75 tap drill
- M14 x 2 tap drill
- M16 x 2 tap drill
- M18 x 2.5 tap drill
- M20 x 2.5 tap drill
- M22 x 2.5 tap drill
- M24 x 3 tap drill
- M27 x 3 tap drill
- M30 x 3.5 tap drill
- M8 x 1 tap drill
- M10 x 1.25 tap drill
- M10 x 1 tap drill
- M12 x 1.5 tap drill
- M12 x 1.25 tap drill
- M14 x 1.5 tap drill
- M16 x 1.5 tap drill
- M18 x 1.5 tap drill
- M20 x 1.5 tap drill
- M22 x 1.5 tap drill
- M24 x 2 tap drill