<font color='black' size='2' face='Georgia, Times New Roman, Times, Serif'><span class="Apple-style-span" style="font-family: Georgia, 'Times New Roman', Times, serif; font-size: 13px; ">I </span><font class="Apple-style-span" size="2" style="font-family: Georgia, 'Times New Roman', Times, serif; ">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. </font> <div><font class="Apple-style-span" size="2" style="font-family: Georgia, 'Times New Roman', Times, serif; ">Regards, </font><br> <br> <div style="font-family: Georgia, 'Times New Roman', Times, serif; font-size: 13px; clear: both; "><font color="black" face="arial" size="2">Ed Foote RPT<br> http://www.piano-tuners.org/edfoote/index.html</font></div> <br> <div style="color: black; "> <div id="AOLMsgPart_1_67632b42-6e7b-40a8-a14e-f752bf0d18c8"> <div> <div><blockquote type="cite"> <div><font class="Apple-style-span" face="Georgia, 'Times New Roman', Times, serif" style="font-size: 10pt; "> <br> </font><font class="Apple-style-span" face="Georgia, 'Times New Roman', Times, serif" size="2">>></font></div> <div><font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">The agraffes that break have a flat bottomed shoulder and the stud isn't </font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">threaded all the way up to the shoulder. When these were installed, the </font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">stud ran out of thread before the shoulder seated, so they just cranked </font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">them on down in spite of it. This over stressed the stud. When they did </font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">bottom out, the flat bottomed shoulder wasn't crushable like the concave </font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">shoulders in the supply house agraffes we get now. So when they cranked </font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">them even harder to align them it stressed the stud even more.</font><br> <br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">When they eventually break, the stud threads are still jammed into the </font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">plate threads, making the broken stud hard to get out.</font><br> <br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">That's pretty much it.</font><br> <font class="Apple-style-span" face="helvetica, arial" style="font-size: 10pt; ">Ron N</font><br> <br> </div> </blockquote></div> <br> </div> </div>  </div> </div> </font>