1/64 inch in mm and decimal

1/64 in = 0.015625 in = 0.397 mm. Closest metric drill: 1 mm.

Nearby drill sizes

Drill	Type	Inch	mm	Difference
#80	number	.0135 in	0.343	-2.1 thou
#79	number	.0145 in	0.368	-1.1 thou
1/64	fraction	.0156 in	0.397	0.0 thou
#78	number	.0160 in	0.406	0.4 thou
#77	number	.0180 in	0.457	2.4 thou
#76	number	.0200 in	0.508	4.4 thou
#75	number	.0210 in	0.533	5.4 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.