"Oval or Round Shanks"

[Antares]

Dear colleagues,
One of the things I have heard about, is affecting the tone (of a grand piano) by working on the hammer shank. 
At one time, I was for a learning period in the Bösendorfer factory, and I had trouble with tuning a certain tone in the treble.
I complained about this to the instructor, and what he did amazed me....
First he took out the action, pulled the hammers upwards, and tapped on the heads with a piece of wood.
He then discovered that the hammer that gave me trouble, gave a different sound. it was either higher or lower in pitch.
He took out the hammer, pulled off the hammerhead and replaced the shank with another one after having made sure that the pitch of the hammershank was about the same as the neighboring shanks. 
After this procedure tuning was, as I recently learned from you (english speaking) guys, "a breeze"...(I like that one! and I will now use it many times... so if you already know yet a new expression, do >yourself< a favour!!!)

Now...I do understand why the treble hammers in more expensive instruments have been made thinner, but I have also heard, that one could "voice" the sound by "working" on the shank, by scraping off some wood hear and there.
I do not have actual experience with this and I am sure that amongst us there will be some giant who has more accurate knowledge about this.

As I read many posts about oval and round shanks, I understand that the issue is weight and volume (w&v).
I am for the moment however curious about the alteration of the shank, not for the sake of loudness, but for subtle changes in timbre.

I will patiently wait behind my box, and hope for the best (a breeze)...



Friendly greetings from :
          
CONCERT PIANO SERVICE
André Oorebeek
Amsterdam, the Netherlands
       
‰  where MUSIC is no harm can be  ‰