[pianotech] broken agraffes

[Isaac Sadigursky]

Hi,  Ron!
Steinways  with serial numbers #350,000 through 265,000 are notorious  
for that problem;The stem was NOT Threaded to the end and Agraffe  
Installers Over-stressed them during installation process.
Another Notable problem in modern pianos;
On many  Asian  pianos Agraffe Holes are NOT  Drilled all the way  
through the plate and they are Over-stressed.
Just did a 'Root-Canal"  on a Hyundai,about 8 years old..
Hope,this information helps..
On most pianos the only tool I use is modified screwdriver in shape of  
a 'V" or 'Fish Tale'.
It "bites"  into the broken piece and makes removal easy,because it  
grabs 2 points.
Nothing new in this department.
Greetings from rainy Southern California
Isaac Sadigursky, RPT
Los Angeles Chapter


On Jan 23, 2012, at 9:43 AM, Ron Nossaman wrote:

> On 1/23/2012 10:40 AM, Wally Scherer wrote:
>
>> It seems that Steinways are notable for this problem. (WHY?)
>
> The agraffes that break have a flat bottomed shoulder and the stud  
> isn't threaded all the way up to the shoulder. When these were  
> installed, the stud ran out of thread before the shoulder seated, so  
> they just cranked them on down in spite of it. This over stressed  
> the stud. When they did bottom out, the flat bottomed shoulder  
> wasn't crushable like the concave shoulders in the supply house  
> agraffes we get now. So when they cranked them even harder to align  
> them it stressed the stud even more.
>
> When they eventually break, the stud threads are still jammed into  
> the plate threads, making the broken stud hard to get out.
>
> That's pretty much it.
> Ron N