40 mm Drill Size

metric drill

40 mm 1.5748 in 40.00 mm

A 40 mm drill is the standard tap drill for M42 x 2.

What a 40 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 40 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
M42 x 2 chart drill	77.0%	40 mm	77.0%
M42 x 3	51.3%	39 mm	77.0%

Other jobs for a 40 mm

Form-tap hole: The published roll-tap hole for M42 x 4.5. A form tap displaces metal instead of cutting it, so it needs this larger hole.

Drills either side

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

40 mm drill: common questions

What size is a 40 mm drill?

1.5748 inches, which is 40.00 mm. It is a metric drill.

What can I tap with a 40 mm drill?

2 threads: M42 x 2 at 77.0%, M42 x 3 at 51.3%.

Is a 40 mm drill the standard tap drill for anything?

Yes, for M42 x 2 (77.0% thread). That is the size published tap and drill charts give.

What drill is next to a 40 mm?

Down: 39 mm at 1.5354 in. Up: 1-37/64 in at 1.5781 in.