15.9 mm Drill Size

metric drill

15.9 mm 0.626 in 15.90 mm

A 15.9 mm drill measures 0.626 in. It taps 2 threads in this chart.

What a 15.9 mm 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 15.9 mm 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	80.8%	16 mm	77.0%
M18 x 2.5	64.7%	15.5 mm	77.0%

Drills either side

5/8″ 0.625 in · 15.88 mm Next size down
16 mm 0.6299 in · 16 mm Next size up

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

15.9 mm drill: common questions

What size is a 15.9 mm drill?

0.626 inches, which is 15.90 mm. It is a metric drill.

What can I tap with a 15.9 mm drill?

2 threads: M18 x 2 at 80.8%, M18 x 2.5 at 64.7%.

What drill is next to a 15.9 mm?

Down: 5/8 in at 0.625 in. Up: 16 mm at 0.6299 in.