Pin Torque

BSimon1234@AOL.COM BSimon1234@AOL.COM
Thu, 25 Mar 1999 22:40:54 EST


Avery Todd, RPT.,  wrote:

<<Since torque readings have come up, what IS a good torque reading?>>

Good question.

First - how to measure. 
( If anyone does this differently, I would like to hear about your method.) 
 Tune two strings of a unison beatless. Then with a square tip on a 1/4" drive
torque wrench, one that reads from 0 to 200 inch pounds, or even a smaller
torque range, slowly and gradually apply reverse torque to a pin, trying to
make it go down in pitch.  Watch the reading on the scale until you just hear
the two strings start to detune. That is the reading I am looking for.

I feel the minimum torque value for really sound tuning is perhaps 18-22 inch
pounds, but it varies with diffferent pianos due to friction points.  I have
several customers with pianos in the 14-18 in/lb range and their pianos are
solid, year after year.  I think it is a combination of particularly good
friction on the capo bar and the fact they play softly. I cannot remember
seeing a piano with 12 in/lbs range that was tuneable. On the good side, I
cannot remember a piano with torque readings above 25 in/lbs that was not
tuneable. (because of torque)

Good question - hope there is a lot of feedback.

Bill Simon
Phoenix



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