61/64 in Drill Size

fractional drill

61/64″ 0.9531 in 24.21 mm

A 61/64 in drill is the standard tap drill for 1-20.

What a 61/64 in 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 61/64 in drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
1-20 chart drill	72.2%	61/64″	72.2%
M27 x 3	71.6%	24 mm	77.0%

Drills either side

24 mm 0.9449 in · 24 mm Next size down
24.5 mm 0.9646 in · 24.5 mm Next size up

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

61/64 in drill: common questions

What size is a 61/64 in drill?

0.9531 inches, which is 24.21 mm. It is a fractional drill.

What can I tap with a 61/64 in drill?

2 threads: 1-20 at 72.2%, M27 x 3 at 71.6%.

Is a 61/64 in drill the standard tap drill for anything?

Yes, for 1-20 (72.2% thread). That is the size published tap and drill charts give.

What drill is next to a 61/64 in?

Down: 24 mm at 0.9449 in. Up: 24.5 mm at 0.9646 in.