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O drill bit size
O drill = .3160 in = 8.03 mm. Closest metric drill: 8 mm.
Nearby drill sizes
| Drill | Type | Inch | mm | Difference |
|---|---|---|---|---|
| M | letter | .2950 in | 7.493 | -21.0 thou |
| 19/64 | fraction | .2969 in | 7.541 | -19.1 thou |
| N | letter | .3020 in | 7.671 | -14.0 thou |
| 5/16 | fraction | .3125 in | 7.938 | -3.5 thou |
| O | letter | .3160 in | 8.026 | 0.0 thou |
| P | letter | .3230 in | 8.204 | 7.0 thou |
| 21/64 | fraction | .3281 in | 8.334 | 12.1 thou |
| Q | letter | .3320 in | 8.433 | 16.0 thou |
| R | letter | .3390 in | 8.611 | 23.0 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.