20.5 mm Drill Size

metric drill

20.5 mm 0.8071 in 20.50 mm

A 20.5 mm drill is the standard tap drill for M22 x 1.5.

What a 20.5 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 20.5 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
M22 x 1.5 chart drill	77.0%	20.5 mm	77.0%
7/8-14	73.2%	13/16″	67.4%
M22 x 2	57.7%	20 mm	77.0%

Other jobs for a 20.5 mm

Hard-material tap drill: The size to use in stainless or tool steel for M22 x 2, where it leaves a shallower thread than the standard drill and cuts tapping torque.

Drills either side

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

20.5 mm drill: common questions

What size is a 20.5 mm drill?

0.8071 inches, which is 20.50 mm. It is a metric drill.

What can I tap with a 20.5 mm drill?

3 threads: M22 x 1.5 at 77.0%, 7/8-14 at 73.2%, M22 x 2 at 57.7%.

Is a 20.5 mm drill the standard tap drill for anything?

Yes, for M22 x 1.5 (77.0% thread). That is the size published tap and drill charts give.

What drill is next to a 20.5 mm?

Down: 51/64 in at 0.7969 in. Up: 13/16 in at 0.8125 in.