Simple Drill and Tap Chart - INCH
Every tool site has a Drill and Tap Chart. They are stuffed with lots of useless information and are often so small you need a magnifying glass to read them. Here is a simple and concise version that should be useful on a phone or tablet. These tables are for National Thread, Imperial (inch) organized by Course, Fine and finally Pipe threads. Your eyes will thanks me later! If you need a size not listed better hit up Google!
Looking for other Tap and Drill Guides?
Click for the Metric Tap and Drill Chart
Click for the British Tap and Drill Chart
| Tap and Drill Chart - National Coarse Threads Inch |
| Thread |
Drill Size |
Decimal Equivalent |
| #4-40 |
43 |
0.0890 |
| #6-32 |
36 |
0.1065 |
| #8-32 |
29 |
0.1360 |
| #10-24 |
25 |
0.1495 |
| #12-24 |
16 |
0.1770 |
| 1/4-20 |
7 |
0.2010 |
| 5/16-18 |
F |
0.2570 |
| 3/8-16 |
5/16 |
0.3125 |
| 7/16-14 |
U |
0.3680 |
| 1/2-13 |
27/64 |
0.4219 |
| 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 |
0.8750 |
| Tap and Drill Chart - National Fine Threads Inch |
| Thread |
Drill Size |
Decimal Equivalent |
| #4-48 |
42 |
0.0935 |
| #6-40 |
33 |
0.1130 |
| #8-36 |
29 |
0.1360 |
| #10-32 |
21 |
0.1590 |
| #12-28 |
14 |
0.1820 |
| 1/4-28 |
3 |
0.2130 |
| 5/16-24 |
I |
0.2720 |
| 3/8-24 |
Q |
0.3320 |
| 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 |
15/16 |
0.9375 |
| Tap and Drill Chart - Tapered Pipe Threads (NPT) Inch |
| Thread |
Drill Size |
Decimal Equivalent |
| 1/16-27 |
D |
0.2460 |
| 1/8-27 |
R |
0.3390 |
| 1/4-18 |
7/16 |
0.4375 |
| 3/8-18 |
37/64 |
0.5781 |
| 1/2-14 |
23/32 |
0.7187 |
| 3/4-14 |
59/64 |
0.9219 |
| 1-11.5 |
1-5/32 |
1.1562 |
