Tap Drill Size Chart

17.8 mm Drill Size

metric drill

17.8 mm 0.7008 in 17.80 mm

A 17.8 mm drill measures 0.7008 in. It taps 4 threads in this chart.

What a 17.8 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 17.8 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 2 84.7% 18 mm 77.0%
3/4-20 75.7% 45/64″ 72.2%
M20 x 2.5 67.7% 17.5 mm 77.0%
3/4-16 60.6% 11/16″ 77.0%

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17.8 mm drill: common questions

What size is a 17.8 mm drill?
0.7008 inches, which is 17.80 mm. It is a metric drill.
What can I tap with a 17.8 mm drill?
4 threads: M20 x 2 at 84.7%, 3/4-20 at 75.7%, M20 x 2.5 at 67.7%, 3/4-16 at 60.6%.
What drill is next to a 17.8 mm?
Down: 17.7 mm at 0.6969 in. Up: 45/64 in at 0.7031 in.