G drill bit size

G drill = .2610 in = 6.63 mm. Closest metric drill: 6.6 mm.

Nearby drill sizes

Drill	Type	Inch	mm	Difference
D	letter	.2460 in	6.248	-15.0 thou
E	letter	.2500 in	6.350	-11.0 thou
1/4	fraction	.2500 in	6.350	-11.0 thou
F	letter	.2570 in	6.528	-4.0 thou
G	letter	.2610 in	6.629	0.0 thou
17/64	fraction	.2656 in	6.747	4.6 thou
H	letter	.2660 in	6.756	5.0 thou
I	letter	.2720 in	6.909	11.0 thou
J	letter	.2770 in	7.036	16.0 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.