#5 drill bit size
0.2055 in
5.22 mm · number drill
| Inches | 0.2055 in |
| Millimetres | 5.22 mm |
| Nearest metric drill | 5.2 mm |
| System | Number (#1 to #60) |
What #5 means
A bit marked #5 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 #5:
| System | Nearest size | Difference |
|---|---|---|
| letter | A — 0.234 in | 0.0285 in larger |
| fractional | 13/64" — 0.2031 in | 0.0024 in smaller |
| metric | 5.2 mm | 0.02 mm smaller |
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 0.2055 inches
Where the quarter-inch and five-sixteenths taps are drilled, and where clearance holes for small bolts begin. The three drill systems overlap most densely across this band, which is why a bit here is the one most often picked up and misidentified.
Either side of it
| Drill | Inches | Millimetres |
|---|---|---|
| #7 | 0.201 in | 5.11 mm |
| 13/64" | 0.2031 in | 5.16 mm |
| #6 | 0.204 in | 5.18 mm |
| #5 | 0.2055 in | 5.22 mm |
| #4 | 0.209 in | 5.31 mm |
| #3 | 0.213 in | 5.41 mm |
| 7/32" | 0.2188 in | 5.56 mm |
Frequently asked questions
What size is a #5 drill bit?
0.2055 inches, which is 5.22 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 #5 drill bit in mm?
5.22 mm. A metric index will offer 5.2 mm as the nearest stocked size, which is near enough identical.
Is #5 a tapping drill size?
Not for any of the unified threads on this site. It sits between the sizes the standard taps call for, so it is a clearance or pilot drill rather than a tapping one.
What is the next size up from #5?
#4 at 0.209 inches — 0.0035 inches larger. Below it is #6 at 0.204.
Other sizes
- #4 drill bit — 0.209 in, 5.31 mm
- #3 drill bit — 0.213 in, 5.41 mm
- 7/32" drill bit — 0.2188 in, 5.56 mm
- #2 drill bit — 0.221 in, 5.61 mm
- #1 drill bit — 0.228 in, 5.79 mm
- A drill bit — 0.234 in, 5.94 mm
- 15/64" drill bit — 0.2344 in, 5.95 mm
- B drill bit — 0.238 in, 6.05 mm