5/64" drill bit size
0.0781 in
1.98 mm · fractional drill
| Inches | 0.0781 in |
| Millimetres | 1.98 mm |
| Nearest metric drill | 2 mm |
| System | Fractional (64ths) |
What 5/64" means
5/64" 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 5/64":
| System | Nearest size | Difference |
|---|---|---|
| number | #47 — 0.0785 in | 0.0004 in larger |
| letter | A — 0.234 in | 0.1559 in larger |
| metric | 2 mm | 0.016 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 gets drilled at 0.0781 inches
This is circuit-board and small-pin range — component leads, header pins, the holes a hobbyist drills in perfboard. It is also where the smallest machine-screw taps live, so a drill here is as likely to be preparing a thread as clearing a wire.
Either side of it
| Drill | Inches | Millimetres |
|---|---|---|
| #50 | 0.07 in | 1.78 mm |
| #49 | 0.073 in | 1.85 mm |
| #48 | 0.076 in | 1.93 mm |
| 5/64" | 0.0781 in | 1.98 mm |
| #47 | 0.0785 in | 1.99 mm |
| #46 | 0.081 in | 2.06 mm |
| #45 | 0.082 in | 2.08 mm |
Frequently asked questions
What size is a 5/64" drill bit?
0.0781 inches, which is 1.98 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 5/64" drill bit in mm?
1.98 mm. A metric index will offer 2 mm as the nearest stocked size, which is near enough identical.
Is 5/64" a tapping drill size?
Not for any of the unified threads on this site. The next size up, #47, is the tapping drill for 3-48.
What is the next size up from 5/64"?
#47 at 0.0785 inches — 0.0004 inches larger. Below it is #48 at 0.076.
Other sizes
- #47 drill bit — 0.0785 in, 1.99 mm
- #46 drill bit — 0.081 in, 2.06 mm
- #45 drill bit — 0.082 in, 2.08 mm
- #44 drill bit — 0.086 in, 2.18 mm
- #43 drill bit — 0.089 in, 2.26 mm
- #42 drill bit — 0.0935 in, 2.37 mm
- 3/32" drill bit — 0.0938 in, 2.38 mm
- #41 drill bit — 0.096 in, 2.44 mm