Tap Drill Size Chart

6.8 mm Drill Size

metric drill

6.8 mm 0.2677 in 6.80 mm

A 6.8 mm drill is the standard tap drill for M8 x 1.25.

What a 6.8 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 6.8 mm drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread % thread Chart drill Chart %
5/16-24 82.8% I 74.8%
M8 x 1.25 chart drill 73.9% 6.8 mm 73.9%
5/16-18 62.1% F 76.9%

Drills either side

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6.8 mm drill: common questions

What size is a 6.8 mm drill?
0.2677 inches, which is 6.80 mm. It is a metric drill.
What can I tap with a 6.8 mm drill?
3 threads: 5/16-24 at 82.8%, M8 x 1.25 at 73.9%, 5/16-18 at 62.1%.
Is a 6.8 mm drill the standard tap drill for anything?
Yes, for M8 x 1.25 (73.9% thread). That is the size published tap and drill charts give.
What drill is next to a 6.8 mm?
Down: H at 0.266 in. Up: 6.9 mm at 0.2717 in.