#23 Drill Size

number drill

#23 0.154 in 3.91 mm

A #23 drill measures 0.154 in. It taps 1 thread in this chart.

What a #23 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 #23 drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
#10-24	66.5%	#25	74.8%

Other jobs for a #23

Clearance hole: The through hole a bolt passes in, not a tapped hole: close fit for #6-32, close fit for #6-40. See the clearance hole chart.

Drills either side

#24 0.152 in · 3.86 mm Next size down
5/32″ 0.1562 in · 3.97 mm Next size up

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

#23 drill: common questions

What size is a #23 drill?

0.154 inches, which is 3.91 mm. It is a number drill.

What can I tap with a #23 drill?

1 thread: #10-24 at 66.5%.

Is a #23 drill used for clearance holes?

Yes: close fit for #6-32, close fit for #6-40. A clearance hole is not tapped; the bolt passes through it.

What drill is next to a #23?

Down: #24 at 0.152 in. Up: 5/32 in at 0.1562 in.