While Drilling is the process of making holes in a material (wood, masonry, metal, etc.), Tapping is the process of creating threads inside those holes for inserting screws. In the previous guide, we saw Drill Sizes Chart for various standards. But if you want to properly insert screws in the holes, then you need a Tap Drill Chart. So, in this guide, let us take a quick look at different Tap Drill Charts based on different standards.
Outline
ToggleA Brief Note on Drill and Tap
The combination of Drills and Drill Bits allow you to make holes in wood, bricks, concrete, metal and other materials. If you want to insert screws or bolts into these holes, then you need proper threaded walls on the holes. This is where a ‘Tap’ comes into play.
It is a tool that can create screw threads in holes created by drills. The process of creating threads in drill holes is known as Tapping.
Tap Drill Chart
Just like other sizes, even Tap Drill Sizes are available in both metric and imperial. We will take a look at different tap drill charts based on the drill sizes.
Number Size Tap Drill Chart
Tap Size | Drill Size | Decimal Value (in) |
0 – 80 | 3/64” | 0.0469 |
1 – 64 | #53 | 0.0595 |
1 – 72 | #53 | 0.0595 |
2 – 56 | #50 | 0.07 |
2 – 64 | #50 | 0.07 |
3 – 48 | #47 | 0.0785 |
3 – 56 | #46 | 0.081 |
4 – 40 | #43 | 0.089 |
4 – 48 | #42 | 0.0935 |
5 – 40 | #38 | 0.1015 |
5 – 44 | #37 | 0.104 |
6 – 32 | #36 | 0.1065 |
6 – 40 | #33 | 0.113 |
8 – 32 | #29 | 0.136 |
8 – 36 | #29 | 0.136 |
10 – 24 | #26 | 0.147 |
10 – 32 | #21 | 0.159 |
12 – 24 | #16 | 0.177 |
12 – 28 | #15 | 0.18 |
14 – 20 | #10 | 0.1935 |
14 – 24 | #7 | 0.201 |
Metric Tap Drill Chart
Tap Size | Drill Size (mm) | Decimal Value (in) |
M1.6 × 0.35 | 1.25 | 0.0492 |
M1.8 × 0.35 | 1.45 | 0.0571 |
M2 × 0.4 | 1.6 | 0.063 |
M2.2 × 0.45 | 1.75 | 0.0689 |
M2.5 × 0.45 | 2.05 | 0.0807 |
M3 × 0.5 | 2.5 | 0.0984 |
M3.5 × 0.6 | 2.9 | 0.1142 |
M4 × 0.7 | 3.3 | 0.1299 |
M4.5 × 0.75 | 3.7 | 0.1476 |
M5 × 0.8 | 4.2 | 0.1654 |
M6 × 1.0 | 5 | 0.1969 |
M7 × 1.0 | 6 | 0.2362 |
M8 × 1.25 | 6.7 | 0.2638 |
M8 × 1.0 | 7 | 0.2756 |
M10 × 1.5 | 8.5 | 0.3346 |
M10 × 1.25 | 8.7 | 0.3425 |
M12 × 1.75 | 10.2 | 0.4016 |
M12 × 1.25 | 10.8 | 0.4252 |
M14 × 2.0 | 12 | 0.4224 |
M16 × 2.0 | 14 | 0.5512 |
M16 × 1.5 | 14.5 | 0.5906 |
M18 × 2.5 | 15.5 | 0.6102 |
M18 × 1.5 | 16.5 | 0.6496 |
M20 × 2.5 | 17.5 | 0.689 |
M20 × 1.5 | 18.5 | 0.7283 |
M22 × 2.5 | 19.5 | 0.7677 |
M22 × 1.5 | 20.5 | 0.8071 |
M24 × 3.0 | 21 | 0.8268 |
M24 × 2.0 | 22 | 0.8661 |
M27 × 3.0 | 24 | 0.9449 |
M27 × 2.0 | 25 | 0.9843 |
M30 × 3.5 | 26.5 | 1.0433 |
M30 × 2.0 | 28 | 1.1024 |
M33 × 3.5 | 29.5 | 1.1614 |
M33 × 2.0 | 31 | 1.2205 |
M36 × 4.0 | 32 | 1.2598 |
M36 × 3.0 | 33 | 1.2992 |
M39 × 4.0 | 35 | 1.378 |
M39 × 3.0 | 36 | 1.4173 |
Fractional Inch Tap Drill Sizes
Tap Size (in) | Drill Size | Decimal Value (in) |
1/4 – 20 | #7 | 0.201 |
1/4 – 28 | #3 | 0.213 |
5/16 – 18 | F | 0.257 |
5/16 – 24 | I | 0.272 |
3/8 – 16 | 5/16 | 0.3125 |
3/8 – 24 | Q | 0.332 |
7/16 – 14 | U | 0.368 |
7/16 – 20 | 25/64 | 0.3906 |
1/2 – 13 | 27/67 | 0.4219 |
1/2 – 20 | 29/64 | 0.4531 |
9/16 – 12 | 31/64 | 0.4844 |
9/16 – 18 | 33/64 | 0.5156 |
5/8 – 11 | 14/32 | 0.5312 |
5/8 – 18 | 37/64 | 0.5781 |
3/4 – 10 | 21/32 | 0.6562 |
3/4 – 16 | 11/16 | 0.6875 |
7/8 – 9 | 49/64 | 0.7656 |
7/8 – 14 | 13/16 | 0.8125 |
1 – 8 | 7/8 | 0.875 |
1 – 12 | 59/64 | 0.9219 |
1-1/8 – 7 | 63/64 | 0.9844 |
1-1/8 – 12 | 1-3/64 | 1.0469 |
1-1/4 – 7 | 1-7/64 | 1.1094 |
1-1/4 – 12 | 1-11/64 | 1.1719 |
1-3/8 – 6 | 1-7/32 | 1.2188 |
1-3/8 – 12 | 1-19/64 | 1.2969 |
1-1/2 – 6 | 1-11/32 | 1.3438 |
1-1/2 – 12 | 1-27/64 | 1.4219 |
Unified National Coarse Tap Drill Sizes
Tap Size | Drill Size | Decimal Value (in) |
1 – 64 | #53 | 0.0595 |
2 – 56 | #50 | 0.07 |
3 – 48 | #47 | 0.0785 |
4 – 40 | #43 | 0.089 |
5 – 40 | #38 | 0.1015 |
6 – 32 | #36 | 0.1065 |
8 – 32 | #29 | 0.136 |
10 – 24 | #26 | 0.147 |
12 – 24 | #16 | 0.177 |
1/4 – 20 | #7 | 0.201 |
5/16 – 18 | F | 0.257 |
3/8 – 16 | 5/16 | 0.3125 |
7/16 – 14 | U | 0.368 |
1/2 – 13 | 27/64 | 0.368 |
9/16 – 12 | 31/64 | 0.4844 |
5/8 – 11 | 17/32 | 0.5312 |
3/4 – 10 | 21/32 | 0.6562 |
7/8 – 9 | 49/64 | 0.7656 |
1 – 8 | 7/8 | 0.875 |
1-1/8 – 7 | 63/34 | 0.9844 |
1-1/4 – 7 | 1-7/64 | 1.1094 |
1-3/8 – 6 | 1-1/64 | 1.2188 |
1-1/2 – 6 | 1-11/54 | 1.3438 |
Unified National Fine Tap Drill Sizes
Tap Size | Drill Size | Decimal Value (in) |
0 – 80 | 3/64” | 0.0469 |
1 – 72 | #53 | 0.0595 |
2 – 64 | #50 | 0.07 |
3 – 56 | #46 | 0.081 |
4 – 48 | #42 | 0.0935 |
5 – 44 | #37 | 0.104 |
6 – 40 | #33 | 0.113 |
8 – 36 | #29 | 0.136 |
10 – 32 | #21 | 0.159 |
12 – 28 | #15 | 0.18 |
1/4 – 28 | #3 | 0.213 |
5/16 – 24 | I | 0.272 |
3/8 – 24 | Q | 0.332 |
7/16 – 20 | 25/64 | 0.3906 |
1/2 – 20 | 29/64 | 0.4531 |
9/16 – 18 | 33/64 | 0.5156 |
5/8 – 18 | 37/64 | 0.5781 |
3/4 – 16 | 11/16 | 0.6875 |
7/8 – 14 | 13/16 | 0.8125 |
1 – 12 | 59/64 | 0.9219 |
1-1/8 – 12 | 1-3/64 | 1.0469 |
1-1/4 – 12 | 1-11/64 | 1.1719 |
1-3/8 – 12 | 1-19/64 | 1.2969 |
1-1/2 – 12 | 1-27/64 | 1.4219 |
National Standard Tap Drill Sizes
Tap Size | Drill Size |
5/32 – 32 | 1/8 |
5/32 – 36 | #30 |
3/16 – 24 | #26 |
3/16 – 32 | #22 |
7/32 – 24 | #16 |
7/32 – 32 | #12 |
1/4 – 32 | 7/32 |
1/4 – 40 | #1 |
5/16 – 32 | 9/32 |
11/16 – 16 | 5/8 |
1 – 14 | 15/16 |
National Pipe Thread Tap Drill Sizes
Tap Size | Drill Size |
1/8 – 27 | Q |
1/4 – 18 | 7/16 |
3/8 – 18 | 9/16 |
1/2 – 14 | 23/32 |
3/4 – 14 | 59/64 |
1 – 11-1/2 | 1-5/32 |
1-1/4 – 11-1/2 | 1-1/2 |
1-1/2 – 11-1/2 | 1-47/64 |
2 – 11-1/2 | 2-7/32 |
Conclusion
If you want to create screw threads in holes, hen you have to use a Tap (a tool that forms threads). And the process of creating these threads is known as Tapping. Since tapping and Drilling are closely related to each other, if you want to tap a hole, then the diameter of the hole is very important. This is where the Tap Drill Chart can be handy. You can use these charts as a reference to properly drill holes and tap them.