23/64" drill size
A 23/64 in drill is 0.3594 in (9.13 mm). It sits between 11/32 in and 3/8 in in the fractional series; the nearest metric drill is 9.1 mm.
23/64" at a glance
Decimal, metric and the nearest sizes in the other series.
Nearest metric drills
Metric drills step by 0.05 mm below 3 mm and by 0.1 mm from 3 mm. Difference is metric minus inch size.
| Metric drill | Inch | Difference | In inches | Hole |
|---|---|---|---|---|
| 9.1 mm | 0.3583" | −0.028 mm | −0.0011" | Smaller |
| 9.2 mm | 0.3622" | +0.072 mm | +0.0028" | Larger |
Nearby inch drills
The next size down and up in each inch series, so you can pick a substitute from the drawer.
| Drill | Series | Inch | mm | Difference |
|---|---|---|---|---|
| #1 | Number | 0.2280" | 5.79 mm | −0.1314" |
| 11/32" | Fractional | 0.3438" | 8.73 mm | −0.0156" |
| Letter T | Letter | 0.3580" | 9.09 mm | −0.0014" |
| 23/64" | Fractional | 0.3594" | 9.13 mm | this size |
| Letter U | Letter | 0.3680" | 9.35 mm | +0.0086" |
| 3/8" | Fractional | 0.3750" | 9.52 mm | +0.0156" |
Threads a 23/64" drill can tap
Threads from the tap tables on this site that this drill can tap, with the thread percentage it leaves (55–85 % shown).
| Thread | Standard drill | Thread with this drill | Suits |
|---|---|---|---|
| M10 × 1 | 9 mm | 67 % | Good in steel |
| 7/16-14 UNC | U | 84 % | Soft metals, plastics |
Clearance for screws and bolts
Bolts and screws a 23/64" hole clears, with the diametral clearance and the gap each side. Metric sizes are compared with ISO 273.
| Fastener | Diameter | Clearance | Per side | ISO 273, metric only |
|---|---|---|---|---|
| 5/16" bolt | 0.3125" | 0.0469" | 0.0234" | – |
| M8 bolt | 8 mm | 1.13 mm | 0.56 mm | Normal fit (normal 9, loose 10 mm) |
Inch clearance is the drill size minus the basic major diameter. A drilled hole usually cuts slightly oversize.
Fractional drill index
Every size in the series, holes drawn to scale.
Common questions
What size is a 23/64 in drill?
A 23/64 in drill is 0.3594 in, which is 9.13 mm (9.1281 mm exactly).
What is the metric equivalent of a 23/64 in drill?
The nearest metric drill is 9.1 mm, 0.028 mm smaller. The other close size is 9.2 mm.
What thread can I tap with a 23/64 in drill?
It leaves about 67 % thread in M10 × 1 and 84 % in 7/16-14 UNC.
Which number or letter drill is closest to 23/64 in?
Letter T (0.3580 in) is the closest, 0.0014 in smaller.
What does a 23/64 in drill clear?
It clears a M8 bolt with 1.13 mm total clearance (0.56 mm per side); for metric bolts: normal fit.