5/8 in Drill Size

fractional drill

5/8″ 0.625 in 15.88 mm

A 5/8 in drill measures 0.625 in. It taps 2 threads in this chart.

What a 5/8 in drill taps

Every thread this drill cuts between 50% and 85% of thread, deepest first. Outside that band it is the wrong drill for the job, so nothing below that line is listed.

Threads a 5/8 in drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
M18 x 2	81.8%	16 mm	77.0%
M18 x 2.5	65.4%	15.5 mm	77.0%

Drills either side

15.8 mm 0.622 in · 15.8 mm Next size down
15.9 mm 0.626 in · 15.9 mm Next size up

All drill sizes → · Open this drill in the calculator →

5/8 in drill: common questions

What size is a 5/8 in drill?

0.625 inches, which is 15.88 mm. It is a fractional drill.

What can I tap with a 5/8 in drill?

2 threads: M18 x 2 at 81.8%, M18 x 2.5 at 65.4%.

What drill is next to a 5/8 in?

Down: 15.8 mm at 0.622 in. Up: 15.9 mm at 0.626 in.