63/64" drill size
A 63/64 in drill is 0.9844 in (25.00 mm). It sits between 31/32 in and 1 in in the fractional series; the nearest metric drill is 25.0 mm.
63/64" 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 |
|---|---|---|---|---|
| 25.0 mm | 0.9843" | −0.003 mm | −0.0001" | Smaller |
| 25.1 mm | 0.9882" | +0.097 mm | +0.0038" | Larger |
Nearby inch drills
The next size down and up in each inch series, so you can pick a substitute from the drawer.
Threads a 63/64" 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 |
|---|---|---|---|
| M27 × 2 | 25 mm | 77 % | Soft metals, plastics |
Clearance for screws and bolts
Bolts and screws a 63/64" 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 |
|---|---|---|---|---|
| M22 bolt | 22 mm | 3.00 mm | 1.50 mm | Normal fit (normal 24, loose 26 mm) |
| M24 bolt | 24 mm | 1.00 mm | 0.50 mm | Close fit (close 25, normal 26 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 63/64 in drill?
A 63/64 in drill is 0.9844 in, which is 25.00 mm (25.0031 mm exactly).
What is the metric equivalent of a 63/64 in drill?
The nearest metric drill is 25.0 mm, 0.003 mm smaller. The other close size is 25.1 mm.
What thread can I tap with a 63/64 in drill?
It leaves about 77 % thread in M27 × 2.
What does a 63/64 in drill clear?
It clears a M24 bolt with 1.00 mm total clearance (0.50 mm per side); for metric bolts: close fit.