#8-36 UNF tap drill size

#29 drill — 0.1360 in / 3.45 mm (78% thread)

Major Ø 0.1640 in · 36 threads per inch · fine series. The chart pick targets 75% thread; nearby standard drills:

Drill	Decimal (in)	mm	Thread %
#27	0.1440	3.66	55%
9/64	0.1406	3.57	65%
#28	0.1405	3.57	65%
#29	0.1360	3.45	78%

Cut taps only — roll-form taps need a larger hole. 65–75% suits general work; drop toward 55% in tough material. Verify before you cut.

Same size, coarse series: #8-32 UNC