40.5 mm Drill Size

metric drill

40.5 mm 1.5945 in 40.50 mm

A 40.5 mm drill is the standard tap drill for M45 x 4.5.

What a 40.5 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 40.5 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
M45 x 4.5 chart drill	77.0%	40.5 mm	77.0%
M42 x 2	57.7%	40 mm	77.0%

Other jobs for a 40.5 mm

Hard-material tap drill: The size to use in stainless or tool steel for M42 x 2, where it leaves a shallower thread than the standard drill and cuts tapping torque.
Form-tap hole: The published roll-tap hole for M42 x 3. A form tap displaces metal instead of cutting it, so it needs this larger hole.

Drills either side

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40.5 mm drill: common questions

What size is a 40.5 mm drill?

1.5945 inches, which is 40.50 mm. It is a metric drill.

What can I tap with a 40.5 mm drill?

2 threads: M45 x 4.5 at 77.0%, M42 x 2 at 57.7%.

Is a 40.5 mm drill the standard tap drill for anything?

Yes, for M45 x 4.5 (77.0% thread). That is the size published tap and drill charts give.

What drill is next to a 40.5 mm?

Down: 1-19/32 in at 1.5938 in. Up: 46 mm at 1.811 in.