1-1/4-7 UNC tap drill size

1-7/64 drill — 1.1094 in / 28.18 mm (76% thread)

Major Ø 1.2500 in · 7 threads per inch · coarse series. The chart pick targets 75% thread; nearby standard drills:

Drill	Decimal (in)	mm	Thread %
1-9/64	1.1406	28.97	59%
1-1/8	1.1250	28.57	67%
1-7/64	1.1094	28.18	76%
1-3/32	1.0938	27.78	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: 1-1/4-12 UNF