11/16 inch in mm and decimal

11/16 in = 0.6875 in = 17.462 mm. Closest metric drill: 17.5 mm.

Taps that use a 11/16 drill

Drill	Type	Inch	mm	Difference
5/8	fraction	.6250 in	15.875	-62.5 thou
41/64	fraction	.6406 in	16.272	-46.9 thou
21/32	fraction	.6563 in	16.669	-31.3 thou
43/64	fraction	.6719 in	17.066	-15.6 thou
11/16	fraction	.6875 in	17.462	0.0 thou
45/64	fraction	.7031 in	17.859	15.6 thou
23/32	fraction	.7188 in	18.256	31.3 thou
47/64	fraction	.7344 in	18.653	46.9 thou
3/4	fraction	.7500 in	19.050	62.5 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.