3/64 inch in mm and decimal

3/64 in = 0.046875 in = 1.191 mm. Closest metric drill: 1.2 mm.

Taps that use a 3/64 drill

Drill	Type	Inch	mm	Difference
#59	number	.0410 in	1.041	-5.9 thou
#58	number	.0420 in	1.067	-4.9 thou
#57	number	.0430 in	1.092	-3.9 thou
#56	number	.0465 in	1.181	-0.4 thou
3/64	fraction	.0469 in	1.191	0.0 thou
#55	number	.0520 in	1.321	5.1 thou
#54	number	.0550 in	1.397	8.1 thou
#53	number	.0595 in	1.511	12.6 thou
1/16	fraction	.0625 in	1.587	15.6 thou

1 thou = 0.001 in = 0.0254 mm. Drills a few thou apart are usually interchangeable for clearance holes, but not for tap drills or reamer pilots.