Tapered wrestpins [was Re: Corrections For Aaaargh & I Spec Someone Does]

[John Delacour]

At 22:58 +0100 27/9/07, David Boyce wrote:

>"at the same time the pin is tapered and a thicker portion of the 
>pin has moved into a different part of the hole along it's entire 
>length".
>
>I wasn't aware of tuning pins as being tapered.  Of course the 
>*square* is tapered, but surely the threaded part which goes into 
>the pinblock, is parallel?  I just measured on and it's parallel 
>along its length.  If it was tapered, how would you know where to 
>measure, to get the correct thickness measurement for ordering new 
>ones?

I have never seen tapered pins in a piano much after 1905 but 
Kirkman, Brinsmead and probably many other English makers at least 
did use tapered pins either with first with an oblong head and later 
with a square head.  Whether the pins came from Germany or England I 
don't know, but they are of good quality and I have four pianos in 
the shop at the moment with such pins, all of which remain tunable 
after 100 - 130 years, and that's even before anyone has tapped them 
in.  If they should ever work loose, then the slightest tap on the 
head (with the 100 year-old tuning hammer, of course!) suffices to 
tighten them.

Another advantage of the tapered pin is that in the event of a 
re-string with new cylindrical pins, it is possible to use a size 
that is no greater in diameter at the wrestplank face than the 
original pin and yet will be very tight.  All the pianos I mentioned 
taper down from about 6.75 mm, so a 00 pin can be used for the 
re-string and the piano is as new and ready for another couple of 
centuries' work.  In most cases it is possible to restring using the 
original pins, since, owing to the taper, the pin abrades the plank 
far less than a cylindrical pin on turning out, and will need to be 
only a fraction of a millimetre deeper in the plank at the end of the 
job.

So while I agree that to talk of tapered pins in the context of 20th 
century pianos is nonsense, such things did exist and have proved 
their efficacy over a period far longer than the lifespan of most 
modern pianos.

JD