Recent postings to this topic could leave a lay person to believe
that a tuning pin can be set by vigorous pounding on the keys, with
three fingers or some kind of a pounder tool.

A strong blow is usually needed to vibrate the string across its
terminations to help equalize and tension differences between the
speaking length and the non-speaking lengths.  I myself often use
a combination of thumb and one other finger.  However, this does not
set the tuning pin.

Setting the pin can only be done with the hand manipulating the tuning
hammer.  The subtle movements in that hand make or break a good tuning,
not pounding a key in an effort to force the notes into submission.
In fact, many top rate concert tuners do not strike forcefully at all,
I believe Franz Mohr was one.

Jurgen Goering