Tap Drill Size Chart

18.9 mm Drill Size

metric drill

18.9 mm 0.7441 in 18.90 mm

A 18.9 mm drill measures 0.7441 in. It taps 2 threads in this chart.

What a 18.9 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 18.9 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread % thread Chart drill Chart %
M20 x 1 84.7% 19 mm 77.0%
M20 x 1.5 56.5% 18.5 mm 77.0%

Other jobs for a 18.9 mm

Form-tap hole
The published roll-tap hole for M20 x 2.5. A form tap displaces metal instead of cutting it, so it needs this larger hole.

Drills either side

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18.9 mm drill: common questions

What size is a 18.9 mm drill?
0.7441 inches, which is 18.90 mm. It is a metric drill.
What can I tap with a 18.9 mm drill?
2 threads: M20 x 1 at 84.7%, M20 x 1.5 at 56.5%.
What drill is next to a 18.9 mm?
Down: 18.7 mm at 0.7362 in. Up: 19 mm at 0.748 in.