#14 drill bit size
0.182 in
4.62 mm · number drill · tapping drill for 12-28
| Inches | 0.182 in |
| Millimetres | 4.62 mm |
| Nearest metric drill | 4.6 mm |
| System | Number (#1 to #60) |
| Taps | 12-28 |
What #14 means
A bit marked #14 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 #14:
| System | Nearest size | Difference |
|---|---|---|
| letter | A — 0.234 in | 0.052 in larger |
| fractional | 3/16" — 0.1875 in | 0.0055 in larger |
| metric | 4.6 mm | 0.023 mm smaller |
The closest substitute is 0.0055 inches away. For a clearance hole that is nothing; for a tapping hole it moves the thread engagement by several per cent, which is the difference between an easy tap and a broken one.
What #14 is for
#14 is the standard tapping drill for 12-28 at 75% thread engagement. That is not a coincidence of the tables: the theoretical figure for 12-28 works out at 0.1812 inches, and #14 at 0.182 is the nearest drill that exists.
What gets drilled at 0.182 inches
The busiest part of the number series. Tapping drills for machine screws from #4 to #12 sit in here, along with pilot holes for wood screws and clearance for small pins. If a number drill in a workshop is worn out, it is usually one of these.
Either side of it
| Drill | Inches | Millimetres |
|---|---|---|
| #17 | 0.173 in | 4.39 mm |
| #16 | 0.177 in | 4.5 mm |
| #15 | 0.18 in | 4.57 mm |
| #14 | 0.182 in | 4.62 mm |
| #13 | 0.185 in | 4.7 mm |
| 3/16" | 0.1875 in | 4.76 mm |
| #12 | 0.189 in | 4.8 mm |
Frequently asked questions
What size is a #14 drill bit?
0.182 inches, which is 4.62 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 #14 drill bit in mm?
4.62 mm. A metric index will offer 4.6 mm as the nearest stocked size, which is 0.023 mm smaller — enough to matter when tapping and not enough to matter for a clearance hole.
What tap does a #14 drill bit go with?
12-28 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 #14?
#13 at 0.185 inches — 0.003 inches larger. Below it is #15 at 0.18.
Other sizes
- #13 drill bit — 0.185 in, 4.7 mm
- 3/16" drill bit — 0.1875 in, 4.76 mm
- #12 drill bit — 0.189 in, 4.8 mm
- #11 drill bit — 0.191 in, 4.85 mm
- #10 drill bit — 0.1935 in, 4.91 mm
- #9 drill bit — 0.196 in, 4.98 mm
- #8 drill bit — 0.199 in, 5.05 mm
- #7 drill bit — 0.201 in, 5.11 mm