Tap Drill Size Chart

2.1 mm Drill Size

metric drill

2.1 mm 0.0827 in 2.10 mm

A 2.1 mm drill measures 0.0827 in. It taps 3 threads in this chart.

What a 2.1 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 2.1 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread % thread Chart drill Chart %
#3-56 70.3% #45 73.3%
M2.5 x 0.45 68.4% 2.05 mm 77.0%
#3-48 60.2% #47 75.7%

Drills either side

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2.1 mm drill: common questions

What size is a 2.1 mm drill?
0.0827 inches, which is 2.10 mm. It is a metric drill.
What can I tap with a 2.1 mm drill?
3 threads: #3-56 at 70.3%, M2.5 x 0.45 at 68.4%, #3-48 at 60.2%.
What drill is next to a 2.1 mm?
Down: #45 at 0.082 in. Up: 2.15 mm at 0.0846 in.