Decimal
Equivalents, Standard and NPT Drill Sizes, and Sheet Metal Thickness
|
Fraction |
Decimal |
Bolt, Screw, or NPT Fitting
Size |
Tap Drill |
Tap Drill |
Number |
Letter |
Drill Size |
Sheet Metal Gauge (Steel) |
|
|
|
|
|
|
|
|
|
|
|
|
.0135 |
|
|
|
80 |
|
|
|
|
|
.0145 |
|
|
|
79 |
|
|
|
|
|
.0149 |
|
|
|
|
|
|
28 |
|
|
.0179 |
|
|
|
|
|
|
26 |
|
1/64 |
.015625 |
|
|
|
|
|
|
|
|
|
.0239 |
|
|
|
|
|
|
24 |
|
|
.0299 |
|
|
|
|
|
|
22 |
|
1/32 |
.03125 |
|
|
|
|
|
|
|
|
|
.0359 |
|
|
|
|
|
|
20 |
|
3/64 |
.0469 |
|
|
|
|
|
|
|
|
|
.0478 |
|
|
|
|
|
|
18 |
|
|
.0520 |
|
|
|
55 |
|
|
|
|
|
.0595 |
|
|
|
53 |
|
|
|
|
|
.0598 |
|
|
|
|
|
|
16 |
|
|
.0600 |
0-80 |
3/64 |
|
|
|
3/64 / 55 |
|
|
1/16 |
.0625 |
1/16-60 |
3/64 |
.0469 |
|
|
|
|
|
|
.0700 |
|
|
|
50 |
|
|
|
|
|
.730 |
|
|
|
49 |
|
|
|
|
|
.0730 |
|
1-64 |
.0595 |
|
|
53 / 1/16 |
|
|
|
.0730 |
|
1-72 |
.0595 |
|
|
53 / 52 |
|
|
|
.0747 |
|
|
|
|
|
|
14 |
|
|
.0760 |
|
|
|
48 |
|
|
|
|
1/16-27 NPT |
|
1/16-27 NPT |
|
.242 |
|
C |
|
|
|
5/64 |
.078125 |
|
|
|
|
|
|
|
|
|
.0785 |
|
|
|
47 |
|
|
|
|
|
.0810 |
|
|
|
46 |
|
|
|
|
|
.0820 |
|
|
|
45 |
|
|
|
|
|
.0860 |
|
|
|
44 |
|
|
|
|
|
,0860 |
2-56 |
|
.0700 |
|
|
50 / 49 |
|
|
|
,0860 |
2-64 |
|
.0700 |
|
|
50 / 48 |
|
|
3/32 |
.09375 |
3/32-48 |
|
.0760 |
|
|
48 |
|
|
|
.0990 |
3-48 |
|
.0785 |
|
|
47 / 44 |
|
|
|
.0990 |
3-56 |
|
.0785 |
|
|
45 / 43 |
|
|
|
.0980 |
|
|
|
40 |
|
|
|
|
|
.0995 |
|
|
|
39 |
|
|
|
|
|
.1015 |
|
|
|
38 |
|
|
|
|
|
.1040 |
|
|
|
37 |
|
|
|
|
|
.1046 |
|
|
|
|
|
|
12 |
|
|
.1065 |
|
|
|
36 |
|
|
|
|
7/64 |
.109375 |
|
|
|
|
|
|
|
|
|
.1100 |
|
|
|
35 |
|
|
|
|
|
.1110 |
|
|
|
34 |
|
|
|
|
|
.1120 |
4-40 |
|
.0890 |
|
|
43 / 41 |
|
|
|
.1120 |
4-48 |
|
.0890 |
|
|
42 / 40 |
|
|
|
.1130 |
|
|
|
33 |
|
|
|
|
|
.1160 |
|
|
|
32 |
|
|
|
|
|
.1196 |
|
|
|
|
|
|
11 |
|
|
.1200 |
|
|
|
31 |
|
|
|
|
1/8 |
.125 |
1/8-40 |
|
.1015 |
|
|
38 / 7/64 |
|
|
1/8 |
.125 |
5-40 |
|
.1015 |
|
|
38 / 7/64 |
|
|
1/8 |
.125 |
5-44 |
|
.1040 |
|
|
37 /35 |
|
|
1/8-27
NPT |
|
1/8-27 NPT |
|
.332 |
|
Q |
|
|
|
|
.1285 |
|
|
|
30 |
|
|
|
|
|
.1345 |
|
|
|
|
|
|
10 |
|
|
.1360 |
|
|
|
29 |
|
|
|
|
|
.1380 |
6-32 |
|
.1065 |
|
|
36 / 32 |
|
|
|
.1380 |
6-40 |
|
.1130 |
|
|
36 / 31 |
|
|
|
.1640 |
8-32 |
|
.1360 |
|
|
29 / 27 |
|
|
|
.1640 |
8-36 |
|
.1360 |
|
|
29 / 26 |
|
|
|
.1405 |
|
|
|
28 |
|
|
|
|
9/64 |
.140625 |
|
|
|
|
|
|
|
|
|
.1440 |
|
|
|
27 |
|
|
|
|
|
.1470 |
|
|
|
26 |
|
|
|
|
|
.1495 |
|
|
|
25 |
|
|
|
|
|
.1520 |
|
|
|
24 |
|
|
|
|
|
.1540 |
|
|
|
23 |
|
|
|
|
5/32 |
.15625 |
|
|
|
|
|
|
|
|
|
.1570 |
|
|
|
22 |
|
|
|
|
|
.1590 |
|
|
|
21 |
|
|
|
|
|
.1610 |
|
|
|
20 |
|
|
|
|
|
.1660 |
|
|
|
19 |
|
|
|
|
|
.1695 |
|
|
|
18 |
|
|
|
|
11/64 |
.171875 |
|
|
|
|
|
|
|
|
|
.1730 |
|
|
|
17 |
|
|
|
|
|
.1770 |
|
|
|
16 |
|
|
|
|
|
.1800 |
|
|
|
15 |
|
|
|
|
|
.1820 |
|
|
|
14 |
|
|
|
|
|
.1850 |
|
|
|
13 |
|
|
|
|
3/16 |
.1875 |
3/16-24 |
|
.1440 |
|
|
27 |
|
|
3/16 |
.1875 |
3/16-32 |
|
.1540 |
|
|
23 |
|
|
|
.1890 |
|
|
|
12 |
|
|
|
|
|
.1900 |
10-24 |
|
.1495 |
|
|
25 / 20 |
|
|
|
.1900 |
10-32 |
|
.1590 |
|
|
21 / 18 |
|
|
|
.1910 |
|
|
|
11 |
|
|
|
|
|
.1935 |
|
|
|
10 |
|
|
|
|
|
.1960 |
|
|
|
9 |
|
|
|
|
|
.1990 |
|
|
|
8 |
|
|
|
|
|
.2010 |
|
|
|
7 |
|
|
|
|
13/64 |
.203125 |
|
|
|
|
|
|
|
|
|
.2040 |
|
|
|
6 |
|
|
|
|
|
.2055 |
|
|
|
5 |
|
|
|
|
|
.2090 |
|
|
|
4 |
|
|
|
|
|
.2130 |
|
|
|
3 |
|
|
|
|
|
.2160 |
12-24 |
|
.1770 |
|
|
16 / 12 |
|
|
|
.2160 |
12-28 |
|
.1800 |
|
|
14 / 10 |
|
|
7/32 |
.21875 |
7/32-24 |
|
.1770 |
|
|
16 |
|
|
7/32 |
.21875 |
7/32-26 |
|
.1800 |
|
|
15 |
|
|
7/32 |
.21875 |
7/32-28 |
|
.1820 |
|
|
14 |
|
|
|
.2210 |
|
|
|
2 |
|
|
|
|
|
.2280 |
|
|
|
1 |
|
|
|
|
|
.234 |
|
|
|
|
A |
|
|
|
15/64 |
.234375 |
|
|
|
|
|
|
|
|
|
.238 |
|
|
|
|
B |
|
|
|
|
.242 |
|
|
|
|
C |
|
|
|
|
.246 |
|
|
|
|
D |
|
|
|
1/4 |
.250 |
|
|
|
|
E |
|
|
|
1/4 |
.250 |
1/4-20 |
|
.2010 |
|
|
7 / 7/32 |
|
|
1/4 |
.250 |
1/4-28 |
|
.2030 |
|
I |
3 / 1 |
|
|
1/4-18
NPT |
|
1/4-18
NPT |
7/16 |
.438 |
|
|
|
|
|
|
.257 |
|
|
|
|
F |
|
|
|
|
.261 |
|
|
|
|
G |
|
|
|
17/64 |
.265625 |
|
|
|
|
|
|
|
|
|
.266 |
|
|
|
|
H |
|
|
|
|
.272 |
|
|
|
|
I |
|
|
|
|
.277 |
|
|
|
|