Drill Sizes Commonly Used in Electronics

Part of the Circuitbuilding Do-It-Yourself For Dummies Cheat Sheet

Building circuits and other electronics requires a small electric drill, cordless or not. Invest in a small bench-mount drill press if you're installing circuits in project boxes and cabinets so it looks good. This guide shows you drill sizes you'll need:

Size Number	Diameter	Next Largest Fractional Size	Clears Screw Size	For Self-Tapping Screw Size
11	0.191″	13/64″		10
19	0.166″	11/64″	8
21	0.159″	11/64″		10-32
25	0.149″	5/32″		10-24
28	0.140″	9/64″	6
29	0.136″	9/64″		8-32
33	0.113″	1/8″	4
36	0.106″	7/64″		6-32
43	0.089″	3/32″		4-40
44	0.086″	3/32″	2
50	0.070″	5/64″		2-56