49/64" drill size
A 49/64 in drill is 0.7656 in (19.45 mm). It is the standard tap drill for 7/8-9 UNC; the nearest metric drill is 19.4 mm.
49/64" 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 |
|---|---|---|---|---|
| 19.4 mm | 0.7638" | −0.047 mm | −0.0018" | Smaller |
| 19.5 mm | 0.7677" | +0.053 mm | +0.0021" | 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 49/64" 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).
Clearance for screws and bolts
Bolts and screws a 49/64" 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 | 1.45 mm | 0.72 mm | Close fit (close 19, normal 20 mm) |
| 3/4" bolt | 0.7500" | 0.0156" | 0.0078" | – |
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 49/64 in drill?
A 49/64 in drill is 0.7656 in, which is 19.45 mm (19.4469 mm exactly).
What is the metric equivalent of a 49/64 in drill?
The nearest metric drill is 19.4 mm, 0.047 mm smaller. The other close size is 19.5 mm.
What tap uses a 49/64 in drill?
A 49/64 in drill is the standard tap drill for 7/8-9 UNC (about 76 % thread).
What does a 49/64 in drill clear?
It clears a 3/4" bolt with 0.0156" total clearance (0.0078" per side).