#1-64 UNC tap drill size

#53 drill — 0.0595 in / 1.51 mm (67% thread)

Major Ø 0.0730 in · 64 threads per inch · coarse series. The chart pick targets 75% thread; nearby standard drills:

Drill	Decimal (in)	mm	Thread %
#52	0.0635	1.61	47%
1/16	0.0625	1.59	52%
#53	0.0595	1.51	67%
#54	0.0550	1.40	89%

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, fine series: #1-72 UNF