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#31 drill bit size
#31 drill = .1200 in = 3.05 mm. Closest metric drill: 3 mm.
Nearby drill sizes
| Drill | Type | Inch | mm | Difference |
|---|---|---|---|---|
| #35 | number | .1100 in | 2.794 | -10.0 thou |
| #34 | number | .1110 in | 2.819 | -9.0 thou |
| #33 | number | .1130 in | 2.870 | -7.0 thou |
| #32 | number | .1160 in | 2.946 | -4.0 thou |
| #31 | number | .1200 in | 3.048 | 0.0 thou |
| 1/8 | fraction | .1250 in | 3.175 | 5.0 thou |
| #30 | number | .1285 in | 3.264 | 8.5 thou |
| #29 | number | .1360 in | 3.454 | 16.0 thou |
| #28 | number | .1405 in | 3.569 | 20.5 thou |
1 thou = 0.001 in = 0.0254 mm. Drills a few thou apart are usually interchangeable for clearance holes, but not for tap drills or reamer pilots.