Tap Drill Size Chart

16.6 mm Drill Size

metric drill

16.6 mm 0.6535 in 16.60 mm

A 16.6 mm drill measures 0.6535 in. It taps 3 threads in this chart.

What a 16.6 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 16.6 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread % thread Chart drill Chart %
3/4-10 74.3% 21/32″ 72.2%
M18 x 1.5 71.9% 16.5 mm 77.0%
M18 x 2 53.9% 16 mm 77.0%

Drills either side

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16.6 mm drill: common questions

What size is a 16.6 mm drill?
0.6535 inches, which is 16.60 mm. It is a metric drill.
What can I tap with a 16.6 mm drill?
3 threads: 3/4-10 at 74.3%, M18 x 1.5 at 71.9%, M18 x 2 at 53.9%.
What drill is next to a 16.6 mm?
Down: 16.5 mm at 0.6496 in. Up: 21/32 in at 0.6562 in.