4 mm Drill Size

metric drill

4 mm 0.1575 in 4.00 mm

A 4 mm drill measures 0.1575 in. It taps 2 threads in this chart.

What a 4 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 4 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
#10-32	80.1%	#21	76.4%
#10-24	60.0%	#25	74.8%

Drills either side

#22 0.157 in · 3.99 mm Next size down
#21 0.159 in · 4.04 mm Next size up

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

4 mm drill: common questions

What size is a 4 mm drill?

0.1575 inches, which is 4.00 mm. It is a metric drill.

What can I tap with a 4 mm drill?

2 threads: #10-32 at 80.1%, #10-24 at 60.0%.

What drill is next to a 4 mm?

Down: #22 at 0.157 in. Up: #21 at 0.159 in.