[TowerTalk] pipe tap drill size

[jimlux]

Dan Zimmerman N3OX wrote:
> On Thu, Mar 11, 2010 at 2:05 PM, r miles <greenacres113 at charter.net> wrote:
> 
>> I am putting two gusset plates to hold truss supports on my homebrew 30m
>> Moxon. I'm using 1/4'' X 20 bolts. It's  been 40 yr.s since I worked in a
>> machine shop. Don't have the proper hole size chart  for taps anymore.  I
>> assume the hole size to be threaded 1/4 x 20 is less than 3/16''. Anyone
>> have a chart showing the proper size.TNX
>> K9IL
> 
> 
> Jim's got it, but for future reference:
> 
> http://en.wikipedia.org/wiki/Drill_and_tap_size_chart
> 
> <http://en.wikipedia.org/wiki/Drill_and_tap_size_chart>
> 

And sometimes, it's stamped on the shank of the tap.