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Drill Sizes Commonly Used in Electronics

By H. Ward Silver

Part of 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