I don't believe all agraffe fractures are due to lack of thread clearance, I have seen too many of the modern undercut design break. I think it is mainly over-torque at the factory, trying to get them lined up. Even with a "zone" offered by the more crushable lip, it seem they still miss it by enough to occasionally over stress the studs. Regards, Ed Foote RPT http://www.piano-tuners.org/edfoote/index.html >> 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120123/bf8b3166/attachment.htm>
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