#77 drill bit size

#77 drill = .0180 in = 0.46 mm. Closest metric drill: 1 mm.

Nearby drill sizes

Drill	Type	Inch	mm	Difference
#80	number	.0135 in	0.343	-4.5 thou
#79	number	.0145 in	0.368	-3.5 thou
1/64	fraction	.0156 in	0.397	-2.4 thou
#78	number	.0160 in	0.406	-2.0 thou
#77	number	.0180 in	0.457	0.0 thou
#76	number	.0200 in	0.508	2.0 thou
#75	number	.0210 in	0.533	3.0 thou
#74	number	.0225 in	0.571	4.5 thou
#73	number	.0240 in	0.610	6.0 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.