Good question...I would like to know myself. Aging Steinways and Yamahas both have this problem. If I remember correctly older Kawai grands too. I'm referring more to the stick and pop part, as the breakage is more easily explained, as Jon posted. I have no answer either on the sticking and popping. It would have to be either the metal in the agraffe, or perhaps some galvanic reaction between whatever steel was used in the strings and the agraffe.
I have thought about this a lot, and have tried some experiments. Such as, taking a Chinese grand, which had exceptionally poor rendering, fixing the termination angles, and replacing the strings with good steel, but retaining the agraffes after re-profiling them to only 0.5mm contact land inside the agraffe. Rendering was normal after the fixes, but is was a new stringing job, so I don't know whether the previous sticking will return with age or not. But I do suspect the alloy in the strings as well as the agraffe alloy.
I tuned an aged Steinway last year, where the rebuilder retained the agraffes, but bushed the block. I was thinking this might make the rendering job easier, but in fact it was an old steinway bear to tune, so changing the flexibility in the pin did nothing to help the matter.
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
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Original Message:
Sent: 09-25-2020 07:28
From: Jon Page
Subject: Steinway Agraffes
The threads on the shank do not go all the way up to the base. Over tightening them to force alignment stresses the shank. Ron Nossaman posted this photo years ago. This can be relieved by drilling the beginning of the threading in the string frame to accept the untapped portion of the shank.
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Regards,
Jon Page
mailto:jonpage@comcast.net
http://www.pianocapecod.com
Original Message:
Sent: 09-25-2020 01:00
From: Blaine Hebert
Subject: Steinway Agraffes
I may have asked this questions before, but it still peaks my curiosity:
Why do Steinway agraffes stick, pop and break more than other brands?
Are they made of a different metal (bronze? one of the dozens of different types of brass?)
https://en.wikipedia.org/wiki/Brass#Types
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Blaine Hebert
Duarte CA
626-795-5170
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