47/64" drill size
A 47/64 in drill is 0.7344 in (18.65 mm). It sits between 23/32 in and 3/4 in in the fractional series; the nearest metric drill is 18.7 mm.
47/64" 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 |
|---|---|---|---|---|
| 18.6 mm | 0.7323" | −0.053 mm | −0.0021" | Smaller |
| 18.7 mm | 0.7362" | +0.047 mm | +0.0018" | 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 47/64" 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 |
|---|---|---|---|
| M20 × 1.5 | 18.5 mm | 69 % | Good in steel |
Clearance for screws and bolts
Bolts and screws a 47/64" 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 |
|---|---|---|---|---|
| M18 bolt | 18 mm | 0.65 mm | 0.33 mm | Tighter than close fit (19 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 47/64 in drill?
A 47/64 in drill is 0.7344 in, which is 18.65 mm (18.6531 mm exactly).
What is the metric equivalent of a 47/64 in drill?
The nearest metric drill is 18.7 mm, 0.047 mm larger. The other close size is 18.6 mm.
What thread can I tap with a 47/64 in drill?
It leaves about 69 % thread in M20 × 1.5.
What does a 47/64 in drill clear?
It clears a M18 bolt with 0.65 mm total clearance (0.33 mm per side); for metric bolts: tighter than close fit.