David, I agree, counter-clockwise while playing the note, measuring the amount of torque being applied at the point when the pin actually slips and the unison goes of of tune. That's the measure of how much effective resistance the pin has against the pull of the string. A Steinway factory guy told me years ago the acceptable torque is between 60 to 100 inch pounds. In my experience most pianos I deal with out in the field are generally much lower than that, maybe 40 to 50 inch pounds, and time of year will affect your reading.
I read somewhere recently, I think a back issue of the Journal that the proper way to measure torque measure the torque going both flat and going sharp and subtract the two values, sort of like measuring downweight and upweight to find the friction and balance weight. I don't remember the specifics and I don't know the value of going to that extent. I think just measuring the torque necessary to get the pin to slip tells you all you need to know.
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John Gunderson RPT
Neptune City NJ
(732) 740-6674
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Original Message:
Sent: 08-15-2022 15:53
From: David Skolnik
Subject: Measuring tuning pin torque
Is there any difference of opinion as to how we measure torque of a strung pin? My assumption has always been to measure counterclockwise, in direction that reduces tension, understanding that static torque would be more. Does anyone
measureAGAINST the string tension?