1/2 in Drill Size

fractional drill

1/2″ 0.500 in 12.70 mm

A 1/2 in drill measures 0.500 in. It taps 4 threads in this chart.

What a 1/2 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 1/2 in drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
M14 x 1.25	80.1%	12.8 mm	73.9%
M14 x 1.5	66.7%	12.5 mm	77.0%
9/16-12	57.7%	31/64″	72.1%
M14 x 2	50.0%	12 mm	77.0%

Other jobs for a 1/2 in

Hard-material tap drill: The size to use in stainless or tool steel for 9/16-12, 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 →

1/2 in drill: common questions

What size is a 1/2 in drill?

0.500 inches, which is 12.70 mm. It is a fractional drill.

What can I tap with a 1/2 in drill?

4 threads: M14 x 1.25 at 80.1%, M14 x 1.5 at 66.7%, 9/16-12 at 57.7%, M14 x 2 at 50.0%.

What drill is next to a 1/2 in?

Down: 12.6 mm at 0.4961 in. Up: 12.7 mm at 0.500 in.