<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 5.50.4134.600" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face="Comic Sans MS" color=#000080>"Strength-to-weight" = ratio is an elusive parameter. What is strength? What are your sources. At 12% = moisture content the Wood Handbook gives both a specific gravity of 0.35. (These = figures are given for Canadian Sitka and white spruce -- there are no = commercially viable stands of Sitka spruce left in the continental U.S.) The most = important "strength" characteristics are:</FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Modulus of rupture is = 10,100 psi (Sitka) vs 9,100 psi (white). </FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Modulus of elasticity = is 1.63 x 10^6 psi (Sitka) vs 1.45 x 10^6 (white). </FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Compression parallel = to grain (maximum crushing strength) is 5,480 psi (Sitka) vs 5,360 <BR>    psi (white). </FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Compression = perpendicular to grain--fiber stress at proportional limit (fspl) is 590 psi <BR>    (Sitka) vs 500 psi (white). </FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Shear parallel to = grain (maximum shear strength) is 980 psi for both. </FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Other than the above = I'm sure white spruce has a greater "strength-to-weight" ratio than = Sitka.</FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Del</FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=Richard.Brekne@grieg.uib.no href="mailto:Richard.Brekne@grieg.uib.no">Richard Brekne</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> February 05, 2003 5:37 = AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Spruce = Strength/Weight</DIV> <DIV><BR></DIV><TT>Compression strengths for red, white and sikta = spruce at 12 % MC</TT><TT></TT> <P><TT>White 35,700 / 3000</TT> <BR><TT>Sitka 37,700 / 3200</TT> <BR><TT>Red   38,800 / 3800</TT><TT></TT> <P><TT>FWIW</TT> <BR><TT>RicB</TT> <BR>  <BLOCKQUOTE TYPE="CITE">>I thought sitka had a greater = strength/weight ratio. And does white spruce <BR>>have a greater compression = strength? <BR>> <BR>>Terry Farrell <P>Wood Handbook - Look it up. <P>Ron N <P>_______________________________________________ <BR>pianotech = list info: <A = href="https://www.moypiano.com/resources/#archives">http://www.ptg.org= /mailman/listinfo/pianotech</A></P></BLOCKQUOTE> <P>-- <BR>Richard Brekne <BR>RPT, N.P.T.F. <BR>UiB, Bergen, Norway = <BR><A href="mailto:rbrekne@broadpark.no">mailto:rbrekne@broadpark.no</A> = <BR><A = href="http://home.broadpark.no/~rbrekne/ricmain.html">http://home.broad= park.no/~rbrekne/ricmain.html</A> <BR>  </P></BLOCKQUOTE></BODY></HTML>