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

[Ron Nossaman]

> 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). 

I also noticed that until relatively recently, these were 
among the nicest turning most easily controllable pinnings I'd 
seen.


> 2/0 - 7.10mm or approx .280"

Which is why 2/0 Denro pins are smaller than 2/0 ? (whoever's 
system that is, where 2/0 is 0.282").


> 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).

And the twist loaded into a pin to get the bottom of it to 
move in the block depends on the pin material's MOE (which 
doesn't necessarily equate to hardness), it's diameter, it's 
length, it's shape (assume cylindrical), the composition and 
distribution of layers of the block in which it's installed, 
the depth in which it's installed in the block, the surface 
configuration of the portion of the pin buried in the block, 
and the PSI load of the pin from the undersized hole in which 
it's installed. That's all I think of off the top, but it's a 
lot more than a column A or column B assembly kit.


> 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).

There are a few folks out there that are positively STEEPED in 
ancient Steinway statistics. I'd be curious if any of them 
know what sized tuning pins were used through what time periods.


> and- ah yes, new pianos with tight pins - the bane of every technician.

Again, not necessarily. The pins I install in my composite 
blocks are quite tight (in spite of driving a 7.1mm pin into a 
6.8mm hole), and it's a bit of a workout to tune them, but 
everyone I've talked to who has tuned one really likes them. 
The issue isn't so much tightness, as it is controllability.


> -just like new pianos with stiff, sluggish actions are the bane of every 
> pianist.

No argument there.


> 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 think that's most of the problem right there. In order to 
get the spread of torque variation (expected from the drilling 
process) high enough that the loosest range will still be 
functional, they raise the average.

Ron N