#7 Drill Size

number drill

#7 0.201 in 5.11 mm

A #7 drill is the standard tap drill for 1/4-20.

What a #7 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 #7 drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
1/4-20 chart drill	75.4%	#7	75.4%
M6 x 1	68.9%	5 mm	77.0%

Other jobs for a #7

Form-tap hole: The published roll-tap hole for #12-28. A form tap displaces metal instead of cutting it, so it needs this larger hole.

Drills either side

5.1 mm 0.2008 in · 5.1 mm Next size down
13/64″ 0.2031 in · 5.16 mm Next size up

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

#7 drill: common questions

What size is a #7 drill?

0.201 inches, which is 5.11 mm. It is a number drill.

What can I tap with a #7 drill?

2 threads: 1/4-20 at 75.4%, M6 x 1 at 68.9%.

Is a #7 drill the standard tap drill for anything?

Yes, for 1/4-20 (75.4% thread). That is the size published tap and drill charts give.

What drill is next to a #7?

Down: 5.1 mm at 0.2008 in. Up: 13/64 in at 0.2031 in.