hammer shanks

[Ron Nossaman]

>Lots of factories sort their shanks by the sound they make, and some even
>file shanks to conform to some frequency. I have been curious about this
>kind of thing  for quite some time, but have never managed to find out much
>about it. Hammer shank voicing I have heard this procedure called.

I've wondered about it for some time too. Which factories among the "lots"
do this?

Ron N