#16 Drill Size

number drill

#16 0.177 in 4.50 mm

A #16 drill is the standard tap drill for #12-24.

What a #16 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 #16 drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
#12-28	84.1%	#14	73.3%
#12-24 chart drill	72.1%	#16	72.1%

Other jobs for a #16

Form-tap hole: The published roll-tap hole for #10-32. A form tap displaces metal instead of cutting it, so it needs this larger hole.

Drills either side

4.4 mm 0.1732 in · 4.4 mm Next size down
4.5 mm 0.1772 in · 4.5 mm Next size up

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

#16 drill: common questions

What size is a #16 drill?

0.177 inches, which is 4.50 mm. It is a number drill.

What can I tap with a #16 drill?

2 threads: #12-28 at 84.1%, #12-24 at 72.1%.

Is a #16 drill the standard tap drill for anything?

Yes, for #12-24 (72.1% thread). That is the size published tap and drill charts give.

What drill is next to a #16?

Down: 4.4 mm at 0.1732 in. Up: 4.5 mm at 0.1772 in.