#6-40 UNF tap drill size

#33 drill — 0.1130 in / 2.87 mm (77% thread)

Major Ø 0.1380 in · 40 threads per inch · fine series. The chart pick targets 75% thread; nearby standard drills:

Drill	Decimal (in)	mm	Thread %
#32	0.1160	2.95	68%
#33	0.1130	2.87	77%
#34	0.1110	2.82	83%
#35	0.1100	2.79	86%

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: #6-32 UNC