"Lloyd E. Sponenburgh" wrote: But Leo, you need to start with a hardy hole
to accommodate the square shank on the carriage bolt. Then you
grind/file/drill/chisel the top of the hole to the profile you wish for the
head. (clip)
^^^^^^^^^^^^^^^^^
Jim made it clear that he understood the process you were describing, but
that the meaning of "hardy hole" was new to him. To my mind, a hardy hole
is a square hole in the top of an anvil. It is a standard square shape that
is intended to have dies or chisels dropped into it. I don't think one
would want to modify a hardy hole for a particular job. This is what I was
trying to clarify.