5.5 mm Drill Size

metric drill

5.5 mm 0.2165 in 5.50 mm

A 5.5 mm drill measures 0.2165 in. It taps 3 threads in this chart.

What a 5.5 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 5.5 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
1/4-32	82.5%	7/32″	76.9%
1/4-28	72.2%	#3	79.8%
1/4-20	51.6%	#7	75.4%

Drills either side

#3 0.213 in · 5.41 mm Next size down
7/32″ 0.2188 in · 5.56 mm Next size up

All drill sizes → · Open this drill in the calculator →

5.5 mm drill: common questions

What size is a 5.5 mm drill?

0.2165 inches, which is 5.50 mm. It is a metric drill.

What can I tap with a 5.5 mm drill?

3 threads: 1/4-32 at 82.5%, 1/4-28 at 72.2%, 1/4-20 at 51.6%.

What drill is next to a 5.5 mm?

Down: #3 at 0.213 in. Up: 7/32 in at 0.2188 in.