5/8" drill size
A 5/8 in drill is 0.6250 in (15.88 mm). It sits between 39/64 in and 41/64 in in the fractional series; the nearest metric drill is 15.9 mm.
5/8" 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 |
|---|---|---|---|---|
| 15.8 mm | 0.6220" | −0.075 mm | −0.0030" | Smaller |
| 15.9 mm | 0.6260" | +0.025 mm | +0.0010" | 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 5/8" 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 |
|---|---|---|---|
| M18 × 2.5 | 15.5 mm | 65 % | Good in steel |
Clearance for screws and bolts
Bolts and screws a 5/8" 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 |
|---|---|---|---|---|
| M14 bolt | 14 mm | 1.88 mm | 0.94 mm | Normal fit (normal 15.5, loose 16.5 mm) |
| 9/16" bolt | 0.5625" | 0.0625" | 0.0312" | – |
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 5/8 in drill?
A 5/8 in drill is 0.6250 in, which is 15.88 mm (15.8750 mm exactly).
What is the metric equivalent of a 5/8 in drill?
The nearest metric drill is 15.9 mm, 0.025 mm larger. The other close size is 15.8 mm.
What thread can I tap with a 5/8 in drill?
It leaves about 65 % thread in M18 × 2.5.
What does a 5/8 in drill clear?
It clears a 9/16" bolt with 0.0625" total clearance (0.0312" per side).