Number Drill Sizes
This chart shows the diameters of number gauge drills size 80 (the smallest) to size 1 (the largest).
| Drill |
Inch |
mm |
| 80 |
0.0135 |
0.34 |
| 79 |
0.0145 |
0.37 |
| 78 |
0.016 |
0.41 |
| 77 |
0.018 |
0.46 |
| 76 |
0.020 |
0.51 |
| 75 |
0.021 |
0.53 |
| 74 |
0.0225 |
0.57 |
| 73 |
0.024 |
0.61 |
| 72 |
0.025 |
0.64 |
| 71 |
0.026 |
0.66 |
| 70 |
0.028 |
0.71 |
| 69 |
0.029 |
0.74 |
| 68 |
0.031 |
0.79 |
| 67 |
0.032 |
0.81 |
| 66 |
0.033 |
0.84 |
| 65 |
0.035 |
0.89 |
| 64 |
0.036 |
0.91 |
| 63 |
0.037 |
0.94 |
| 62 |
0.038 |
0.97 |
| 61 |
0.039 |
0.99 |
| 60 |
0.040 |
1.02 |
| 59 |
0.041 |
1.04 |
| 58 |
0.042 |
1.07 |
| 57 |
0.043 |
1.09 |
| 56 |
0.0465 |
1.18 |
| 55 |
0.052 |
1.32 |
| 54 |
0.055 |
1.40 |
| 53 |
0.0595 |
1.51 |
| 52 |
0.0635 |
1.61 |
| 51 |
0.067 |
1.70 |
| 50 |
0.070 |
1.78 |
| 49 |
0.073 |
1.85 |
| 48 |
0.076 |
1.93 |
| 47 |
0.0785 |
1.99 |
| 46 |
0.081 |
2.06 |
| 45 |
0.082 |
2.08 |
| 44 |
0.086 |
2.18 |
| 43 |
0.089 |
2.26 |
| 42 |
0.0935 |
2.37 |
| 41 |
0.096 |
2.44 |
| 40 |
0.098 |
2.49 |
| 39 |
0.0995 |
2.53 |
| 38 |
0.1015 |
2.58 |
| 37 |
0.104 |
2.64 |
| 36 |
0.1065 |
2.71 |
| 35 |
0.11 |
2.79 |
| 34 |
0.111 |
2.82 |
| 33 |
0.113 |
2.87 |
| 32 |
0.116 |
2.95 |
| 31 |
0.120 |
3.05 |
| 30 |
0.1285 |
3.26 |
| 29 |
0.136 |
3.45 |
| 28 |
0.14 |
3.56 |
| 27 |
0.144 |
3.66 |
| 26 |
0.147 |
3.73 |
| 25 |
0.150 |
3.81 |
| 24 |
0.152 |
3.86 |
| 23 |
0.154 |
3.91 |
| 22 |
0.157 |
3.99 |
| 21 |
0.159 |
4.04 |
| 20 |
0.161 |
4.09 |
| 19 |
0.166 |
4.22 |
| 18 |
0.170 |
4.32 |
| 17 |
0.173 |
4.39 |
| 16 |
0.177 |
4.50 |
| 15 |
0.18 |
4.57 |
| 14 |
0.182 |
4.62 |
| 13 |
0.185 |
4.70 |
| 12 |
0.189 |
4.80 |
| 11 |
0.191 |
4.85 |
| 10 |
0.193 |
4.90 |
| 9 |
0.196 |
4.98 |
| 8 |
0.199 |
5.05 |
| 7 |
0.201 |
5.11 |
| 6 |
0.204 |
5.18 |
| 5 |
0.205 |
5.21 |
| 4 |
0.209 |
5.31 |
| 3 |
0.213 |
5.41 |
| 2 |
0.221 |
5.61 |
| 1 |
0.228 |
5.79 |
|
Bell Punch Center Finder
T-Slot Nut, 7/16"
