1-1/8-7 UNC tap drill size

63/64 drill — 0.9844 in / 25.00 mm (76% thread)

Major Ø 1.1250 in · 7 threads per inch · coarse series. The chart pick targets 75% thread; nearby standard drills:

Drill	Decimal (in)	mm	Thread %
1-1/64	1.0156	25.80	59%
1	1.0000	25.40	67%
63/64	0.9844	25.00	76%
31/32	0.9688	24.61	84%

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: 1-1/8-12 UNF