Nature of tuning pins, hardness, size and tightness of pins.

[Kendall Ross Bean]

Marcel~
 
Thank you for these observations! You bring up some excellent points.
 
The idea of measuring "cents" of twist before the pin turns in the block is
an intriguing one. I will have to try that! It certainly seems that harder
pins (on the Rockwell scale) might well address the issue of excessive pin
twisting in tight holes and tight blocks. (As might also a larger diameter
pin, see below. -And, of course, not drilling the holes so small that you
can't turn the pins.)
 
And yes, I have noticed that the Japanese (Kawai and Yamaha) pianos usually
come from the factory with small diameter nickel plated metric pins,
corresponding to 0 1/2 size in my old Renner catalog (approximately .271 to
272." pin size). When I restring these pianos retaining the original
pinblock, I usually go to a #1/0 or 2/0 pin. 
 
Just for folks information, The European (metric) sizes listed in the Renner
Hauptcatalog 891 are as follows: 
 
Size
 
2 - 6.60mm or approx. .260"
 
1 - 6.75mm or approx .266"
 
0 1/2 - 6.90mm or approx .272"
 
0 (what we call #1 or 1/0) - 7.00mm or .276"
 
2/0 - 7.10mm or approx .280"
 
3/0 - 7.25mm or approx. .285"
 
4/0 - 7.35mm or approx. .289"
 
5/0 - 7.50mm or approx. .295"
 
6/0 - 7.65mm or approx  .301"
 
As you can see, we may see pianos from Europe or Asia with some very small
diameter pins.
 
These pins are also listed as available in 5 different lengths: 52, 55, 57,
60, and 64mm (corresponding with approximately 2.05 to 2.52. inches. They
are offered in either blued or nckel plated (but no nickel/blued).
 
I read once somewhere that Steinway went to #2/0 pins for the factory
stringing because the added string height above the pinblock caused by the
thickness of the plate webbing (as opposed to an open face pinblock) (and
probably also the absence of tuning pin bushings) required a stouter pin
that wouldn't flex (or flagpole) so much. I think it was in an article in
the PianoTechnician's Journal comparing pianos where the plate webbing
covered the pinblock vs those with open face pinblocks (Paul Larudee's
article in Jan 2002 and Feb 2002 PTJ).
 
Looks don't always get in the way of performance, but we do have to be aware
of when they do.
 
and- ah yes, new pianos with tight pins - the bane of every technician.
 
-just like new pianos with stiff, sluggish actions are the bane of every
pianist.
 
When will they learn that tuning pins don't have to read 200 inch lbs or
more after driving. (Maybe they are used to drilling a block with really
sloppy holes? Has to be drilled in 15 minutes?)
 
I notice that Reblitz in the second edition of his P.S.T.& R. book
recommends a pin tightness immediately after driving of 95 to 110 inch lbs.
This, to me, is a bit on the low side, I prefer to see somewhere between 125
to 145 inch lbs. (But I think Reblitz uses the Delignit block, which in my
experience tends to take a much longer time to loosen up, or ultimately
fails to loosen up at all, after driving the pins, unlike the medium
laminate maple or 1/4 sawn 5 ply maple blocks I prefer to use) For me 125 to
145 results in a nice tunable piano by the time the chippings and shop
tunings are done. From 150 up to 200 inch lbs I feel that someone is making
sure that the piano will not be tunable for years after stringing,
especially with one of those dense multilaminate blocks. And of course,
taking your time, cooling the bit, and drilling nice uniform holes that
aren't burnt or oval helps tremendously.
 
I know some rebuilders and manufacturers want to make sure "those tuning
pins will never get loose" but I doubt that they are thinking about the
tuner and the problems they are creating for him/her. 
 
~Kendall Ross Bean
 
PianoFinders
www.pianofinders.com <http://www.pianofinders.com/> 
e-mail: kenbean at pianofinders.com
 
Connecting Pianos and People
 
 

  _____  

From: Marcel Carey [mailto:mcpianos at hotmail.com] 
Sent: Wednesday, July 09, 2008 3:10 AM
To: Pianotech List
Subject: RE: Nature of tuning pins, why technicians prefer blue





I've been reading this thread with interest. One thing that has not been
mentioned is the steel hardness of different tuning pins brands. I agree
with Dave N. that Diamonds are the best specially for uniformity. And they
are also the hardest on the Rockwell tests.
 
I find this is something that bothers me a lot when tuning new pianos with
tight pins. The pins will twist before they turn in the block. I've measured
over 40¢ dofference with just pin twisting before I could feel them turn in
the block. Of course, the fact that some manufacturers use #0 tuning pins
doesn't help.
 
So, for me actual performance is more important than looks. This is the
point I wanted to add to this discussion.
 
Marcel Carey,
Sherbrooke, QC


  _____  

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