3/64" drill bit size
0.0469 in
1.19 mm · fractional drill · tapping drill for 0-80
| Inches | 0.0469 in |
| Millimetres | 1.19 mm |
| Nearest metric drill | 1.2 mm |
| System | Fractional (64ths) |
| Taps | 0-80 |
What 3/64" means
3/64" is a fractional drill, stepping in 64ths of an inch. Fractional sizes are the coarsest of the three systems, which is why a fractional set alone cannot hit most tapping sizes and why number and letter drills exist at all.
The same hole in the other systems
Three drill systems overlap across this range and a workshop rarely has all three. The nearest bit of each other kind to 3/64":
| System | Nearest size | Difference |
|---|---|---|
| number | #56 — 0.0465 in | 0.0004 in smaller |
| letter | A — 0.234 in | 0.1871 in larger |
| metric | 1.2 mm | 0.009 mm larger |
One of those is within three thousandths of an inch, which is inside the tolerance of most hand-held work — substitute it and nobody will know.
What 3/64" is for
3/64" is the standard tapping drill for 0-80 at 75% thread engagement. That is not a coincidence of the tables: the theoretical figure for 0-80 works out at 0.0478 inches, and 3/64" at 0.0469 is the nearest drill that exists.
What gets drilled at 0.0469 inches
Under fifty thousandths of an inch, a drill is watchmaker and model-maker territory: pinning small parts, clearing wire in an instrument, opening a jet. Bits this fine snap if the work moves at all, which is why they are used in a press or a pin vice rather than a hand drill.
Either side of it
| Drill | Inches | Millimetres |
|---|---|---|
| #58 | 0.042 in | 1.07 mm |
| #57 | 0.043 in | 1.09 mm |
| #56 | 0.0465 in | 1.18 mm |
| 3/64" | 0.0469 in | 1.19 mm |
| #55 | 0.052 in | 1.32 mm |
| #54 | 0.055 in | 1.4 mm |
| #53 | 0.0595 in | 1.51 mm |
Frequently asked questions
What size is a 3/64" drill bit?
0.0469 inches, which is 1.19 mm. Fractional drills step in 64ths of an inch, which is the coarsest of the three systems and the one most home sets contain.
What is a 3/64" drill bit in mm?
1.19 mm. A metric index will offer 1.2 mm as the nearest stocked size, which is near enough identical.
What tap does a 3/64" drill bit go with?
0-80 at the standard 75% thread. That thread comes out at a theoretical diameter this drill is the nearest stocked size to.
What is the next size up from 3/64"?
#55 at 0.052 inches — 0.0051 inches larger. Below it is #56 at 0.0465.
Other sizes
- #55 drill bit — 0.052 in, 1.32 mm
- #54 drill bit — 0.055 in, 1.4 mm
- #53 drill bit — 0.0595 in, 1.51 mm
- 1/16" drill bit — 0.0625 in, 1.59 mm
- #52 drill bit — 0.0635 in, 1.61 mm
- #51 drill bit — 0.067 in, 1.7 mm
- #50 drill bit — 0.07 in, 1.78 mm
- #49 drill bit — 0.073 in, 1.85 mm