Tap Drill Size Chart

1-1/64 in Drill Size

fractional drill

1-1/64″ 1.0156 in 25.80 mm

A 1-1/64 in drill measures 1.0156 in. It taps 2 threads in this chart.

What a 1-1/64 in 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 1-1/64 in drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread % thread Chart drill Chart %
M27 x 1.5 61.7% 25.5 mm 77.0%
1-1/8-7 59.0% 63/64″ 75.8%

Other jobs for a 1-1/64 in

Hard-material tap drill
The size to use in stainless or tool steel for 1-1/8-7, where it leaves a shallower thread than the standard drill and cuts tapping torque.

Drills either side

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

1-1/64 in drill: common questions

What size is a 1-1/64 in drill?
1.0156 inches, which is 25.80 mm. It is a fractional drill.
What can I tap with a 1-1/64 in drill?
2 threads: M27 x 1.5 at 61.7%, 1-1/8-7 at 59.0%.
What drill is next to a 1-1/64 in?
Down: 25.5 mm at 1.0039 in. Up: 26 mm at 1.0236 in.