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<FONT face=Tahoma size=2><B>From:</B> pianotech-bounces@ptg.org
[mailto:pianotech-bounces@ptg.org] <B>On Behalf Of
</B>PAULREVENKOJONES@aol.com<BR><B>Sent:</B> June 25, 2005 2:08
PM<BR><B>To:</B> pianotech@ptg.org<BR><B>Subject:</B> Re: Piano wire =
tensile
strength<BR></FONT><BR></DIV>
<DIV></DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial
FAMILY="SANSSERIF" PTSIZE="10">In a message dated 6/25/2005 =
2:30:14 PM Central
Standard Time, fandrich@pianobuilders.com writes:<BR><BR>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px =
solid; MARGIN-RIGHT: 0px"
TYPE="CITE">I just read something in an old report I've been looking =
at that
strikes me as<BR>odd. Basically it says that piano builders put as =
many as
three or four twists<BR>in bass strings to increase the tensile =
strength of
the core wire. <BR><BR>Does this ring any bells? Does anyone know of =
a piano
manufacturer doing this<BR>(twisting bass strings this much)? Is =
anyone out
there metallurgist enough to<BR>know if there is any validity to =
this
claim?<BR></BLOCKQUOTE>
<DIV><BR><BR>Del:<BR><BR>I've talked with only one older factory =
stringer
(he's unfortunately dead now so confirmation isn't possible) who =
claimed that
he put 3-4 twists in bass strings only to tighten the coils on the =
wire to
avoid buzzing as the core stretched. Of course the tension on the =
coils will
release slightly as well, but I can't figure how tensile strength =
(either
overall or in the components --copper or steel) would be increased by =
twisting
which shortens the wire and would cause the need for slightly lower =
tensions
to account for the difference for pitch. Or do I have that backwards? =
The
ductility of copper doesn't argue logically for higher tensile =
strength except
for the stiffening that results from stretching a wire as in lead in =
stained
glass windows which visibly stiffens when stretched; but that is not =
for
tensile strength, more for shearing strength. The same observation =
would hold
for steel as well?<BR><BR>Paul R-J</FONT></FONT><FONT face="Comic =
Sans MS"
color=#000080><SPAN
class=156180523-25062005> </SPAN></FONT></DIV></BLOCKQUOTE>
<DIV><FONT face="Comic Sans MS" color=#000080><SPAN
class=156180523-25062005><FONT face=Arial
color=#000000></FONT></SPAN></FONT> </DIV>
<DIV><FONT face="Comic Sans MS" color=#000080><SPAN
class=156180523-25062005><FONT face=Arial color=#000000>I have =
heard that some
factory stringers tend to put a couple of twists on the bass strings but =
they
have always said it was to prevent buzzing strings from certain string =
makers.
This was especially true as string lathe speeds started reaching up into =
the
stratosphere.</FONT></SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#000000><SPAN
class=156180523-25062005></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#000000><SPAN =
class=156180523-25062005>Never before
have I heard it said it would increase tensile strength. =
</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#000000><SPAN
class=156180523-25062005></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#000000><SPAN
class=156180523-25062005>Del</SPAN></FONT></DIV></BODY></HTML>