#56 drill bit size
0.0465 in
1.18 mm · number drill
| Inches | 0.0465 in |
| Millimetres | 1.18 mm |
| Nearest metric drill | 1.2 mm |
| System | Number (#1 to #60) |
What #56 means
A bit marked #56 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 #56:
| System | Nearest size | Difference |
|---|---|---|
| letter | A — 0.234 in | 0.1875 in larger |
| fractional | 3/64" — 0.0469 in | 0.0004 in larger |
| metric | 1.2 mm | 0.019 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 0.0465 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 |
|---|---|---|
| #59 | 0.041 in | 1.04 mm |
| #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 |
Frequently asked questions
What size is a #56 drill bit?
0.0465 inches, which is 1.18 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 #56 drill bit in mm?
1.18 mm. A metric index will offer 1.2 mm as the nearest stocked size, which is near enough identical.
Is #56 a tapping drill size?
Not for any of the unified threads on this site. The next size up, 3/64", is the tapping drill for 0-80.
What is the next size up from #56?
3/64" at 0.0469 inches — 0.0004 inches larger. Below it is #57 at 0.043.
Other sizes
- 3/64" drill bit — 0.0469 in, 1.19 mm
- #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