quantity of tons of tension per plate

[David Nereson]

  Greetings,



             I should know this, but I forgot; approxamately
(ballpark) how many tons of tension is on a harp plate when the
piano is tuned to A440? Does this tension increase per size of
piano? In other words, is there more tension on a 9 foot concert
grand than a spinet? Also, on grands, do plate nose blots ever
loosen, that a tuner would ever have to tighten them?



  Thanks in advance,

  Julia Gottshall,

  Reading, PA



      It's just the plate, not a "harp plate."  Yes, you should
tighten the bolts around the perimeter of the plate if they're
loose, such as after a piano has been moved from a humid climate
to a dry one, or after a couple years into the life of a new
piano, and on old ones before raising pitch a long ways.  Try to
distribute the tightening so as not to stress the plate in any
one area.   That's the plate bolts around the perimeter of the
plate I'm talking about.  The nose bolts you should probably
leave alone -- maybe just see if they're snug, but don't crank
them down.

      I've read that the total tension between the hitch pins
and the pin block ranges from roughly 15 tons in a spinet to 20
tons or so in a concert grand.

      --David Nereson, RPT
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