#47 drill bit size
0.0785 in
1.99 mm · number drill · tapping drill for 3-48
| Inches | 0.0785 in |
| Millimetres | 1.99 mm |
| Nearest metric drill | 2 mm |
| System | Number (#1 to #60) |
| Taps | 3-48 |
What #47 means
A bit marked #47 is a number drill, and the number is an index rather than a measurement — the higher the number, the smaller the bit. #1 is 0.228 inches and #60 is 0.04. That is the opposite of the fractional sizes stamped on a home set, which is why a number drill and a fraction of similar appearance can be very different holes.
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 #47:
| System | Nearest size | Difference |
|---|---|---|
| letter | A — 0.234 in | 0.1555 in larger |
| fractional | 5/64" — 0.0781 in | 0.0004 in smaller |
| metric | 2 mm | 0.006 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 #47 is for
#47 is the standard tapping drill for 3-48 at 75% thread engagement. That is not a coincidence of the tables: the theoretical figure for 3-48 works out at 0.0787 inches, and #47 at 0.0785 is the nearest drill that exists.
What gets drilled at 0.0785 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 |
|---|---|---|
| #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 |
| #44 | 0.086 in | 2.18 mm |
Frequently asked questions
What size is a #47 drill bit?
0.0785 inches, which is 1.99 mm. Number drills run from #1 at 0.228 inches down to #60 at 0.04, getting smaller as the number rises — the opposite of what most people expect the first time.
What is a #47 drill bit in mm?
1.99 mm. A metric index will offer 2 mm as the nearest stocked size, which is near enough identical.
What tap does a #47 drill bit go with?
3-48 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 #47?
#46 at 0.081 inches — 0.0025 inches larger. Below it is 5/64" at 0.0781.
Other sizes
- #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
- #40 drill bit — 0.098 in, 2.49 mm