THREADS AND DRILL SIZES
Paul Barton
Tap and Clear Drill Tables
Metric tables give ANSI fractional inch, letter or number drill sizes for tap and clear. The columns are as follows:
Metric thread specification
Nearest drill size to the recommended metric tap drill
Variation (mm) in nominal diameter from the metric size. Negative numbers mean undersize. Generally, the next larger size is used unless the undersize is very close.
Nearest drill size to 105% of the nominal metric fastener diameter
Nominal diameter of the recommended clear drill (mm).
Nominal Drill Size
This is one big table with all the number, letter, fractional inch, and metric sizes sorted by ascending diameter and listed together. If you have ever needed to answer a question like “what is the next size up from a #31?” or “what do I have that is close to 4mm?” you will find this one handy.
Oh how I wish it were unnecessary Disclaimer.
If you have not figured out or cannot understand that you can hurt yourself working with power tools, ignore everything else on this page. DO NOT WORK WITH POWER TOOLS. Better yet have yourself admitted to a rest home, drugged insensible and tied into a geri chair so that you can't hurt yourself or anybody else.
This information is presented in hope that I will be useful. The author makes no claim as to its accuracy, currency or applicability to any particular circumstance. Use at your own risk.