Tuning Pin Size

[larudee@pacbell.net]

|John,

What David is calling #1 and #2 are generally called 1/0 and 2/0, which is the
same as 0 and 00.  the corresponding diameters are .276" and .282" or 7.00mm.
and 7.15mm.  The 6.75mm. pins are the true size 1 pins, the size number
increasing as the diameter decreases.  This size is in the Fletcher and Newman
catalog, but not generally available from U.S. distributers.

For the pros and cons of increasing and decreasing pin size, you may be
interested in the considerations set forth in my article on tuning pin physics
in the January and February issues of the PTG Journal, which are a bit lengthy
to reproduce here.  As for your thoughts about the use of 2/0 pin in new pianos
starting with Steinway (because of their closed pinblock design without
bushings) and then being copied by other (primarily American) manufacturers, I
think that is exactly the case.

Paul Larudee

John Delacour wrote:

> At 8:08 PM -0800 1/23/02, David Love wrote:
> >I just finished restringing a couple of older pianos (Schiedmayer,
> >Schomacker).  Both pianos were originally strung with #1 tuning
> >pins.  This was nice since both blocks were good it allowed me to
> >restring with #2's.  I'm curious when/why companies got in the habit
> >of doing the initial stringing with #2's.  The improved tuning
> >quality of a smaller pin would suggest using a #1, as I believe many
> >Japanese makers do.  I know some rebuilders (Dale Erwin) are also
> >stringing new blocks with #1's.  Is there any compelling reason not
> >to use a #1 pin when installing a new block?
>
> I'm not familiar with American gauges and I gave up using gauge
> numbers after a few months in the trade, since there seemed to be a
> great vagueness about the actual diameters.  Under the old system, #0
> or #00 would be the original size, I think.  However I have found
> most German pianos used either a 6.70 - 6.75 mm. pin or a 6.85 - 6.90
> pin.  Some had a turned thread and some a filed thread.  The evenness
> and sharpness of the thread on the best old pins is not to be found
> on any pin of modern manufacture.  It was most common for makers to
> use a shorter pin (54 - 55 mm) than is generally used nowadays.
>
> I always use a 6.75 mm. pin in a new block and on original blocks I
> am very often able to do the job with a pin 6.90 to 7.00 in diameter,
> provided the piano has not been over-used.  The fact that the many,
> if not most, of the old tuners tuned with a T-hammer, means probably
> that less damage tended to be done by tuners.  The man who taught me
> to tune used a T-hammer on grands till the end of his life!  How he
> managed with Korean pianos, heaven knows.
>
> The French used French-made pins which were even thinner (6.60 mm)
> and a few makers used a tapering pin.  Older Brinsmeads had a pin
> tapering from about 6.75 to 6.50, so it is possible to restring using
> the very smallest cylindrical pin (6.75 mm).
>
> As in so many things, the influence of Steinway practice may have
> raised the size of the original pin.  The unbushed Steinway
> string-plate requires the ise of a longer pin and, to avoid bending,
> a fatter pin is required.
>
> At least that's about how I see it.  I can see no reason for not
> using the smallest pin in a bushed string-plate or an open plank,
> both of which I personally prefer.
>
> Did you have a look at the string tensions on the Schiedmayer?  Frightening!
>
> JD