#29 Drill Size

number drill

#29 0.136 in 3.45 mm

A #29 drill is the standard tap drill for #8-32 and #8-36.

What a #29 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 #29 drill taps, with the percent of thread each one gets and the published chart drill for comparison.
Thread	% thread	Chart drill	Chart %
#8-36 chart drill	77.6%	#29	77.6%
#8-32 chart drill	69.0%	#29	69.0%
M4 x 0.7	60.0%	3.3 mm	77.0%

Drills either side

3.4 mm 0.1339 in · 3.4 mm Next size down
3.5 mm 0.1378 in · 3.5 mm Next size up

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

#29 drill: common questions

What size is a #29 drill?

0.136 inches, which is 3.45 mm. It is a number drill.

What can I tap with a #29 drill?

3 threads: #8-36 at 77.6%, #8-32 at 69.0%, M4 x 0.7 at 60.0%.

Is a #29 drill the standard tap drill for anything?

Yes, for #8-32 (69.0% thread) and #8-36 (77.6% thread). That is the size published tap and drill charts give.

What drill is next to a #29?

Down: 3.4 mm at 0.1339 in. Up: 3.5 mm at 0.1378 in.