[pianotech] Chickering Grand Hammer Flanges?

[Ron Nossaman]

On 7/26/2011 12:04 AM, Joseph Garrett wrote:
> Anyone have an idea the difference of expansion rates of Steel and Brass.
> I'm into a Chickering Grand and am planning on trying to anneal them
> puppies. Reason for asking is wether to remove the screws and drop screws
> or leave them in during the annealing process. Any one have some thoughts?
> Regards,
> Joe

This will give you the numbers. Sometimes the Internet is actually good 
for something.
http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

Brass expands more. So as you heat the things up, the steel screws 
should get looser in the brass, then tight again as everything cools. 
I'm not sure it's been satisfactorily determined whether the whole 
annealing process is worth the trouble though.

Ron N