8.4 mm Drill Size

metric drill

8.4 mm 0.3307 in 8.40 mm

A 8.4 mm drill measures 0.3307 in. It taps 3 threads in this chart.

What a 8.4 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 8.4 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
M10 x 1.5	82.1%	8.5 mm	77.0%
3/8-24	81.8%	Q	79.4%
3/8-16	54.6%	5/16″	77.0%

Drills either side

P 0.323 in · 8.2 mm Next size down
Q 0.332 in · 8.43 mm Next size up

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

8.4 mm drill: common questions

What size is a 8.4 mm drill?

0.3307 inches, which is 8.40 mm. It is a metric drill.

What can I tap with a 8.4 mm drill?

3 threads: M10 x 1.5 at 82.1%, 3/8-24 at 81.8%, 3/8-16 at 54.6%.

What drill is next to a 8.4 mm?

Down: P at 0.323 in. Up: Q at 0.332 in.