The answer from Yamaha

[Dave Nereson]

----- Original Message ----- 
From: "pianolover 88" <pianolover88@hotmail.com>
To: <pianotech@ptg.org>
Sent: Monday, October 18, 2004 4:41 PM
Subject: The answer from Yamaha


> earlier today I spoke with tech  Dave Durbin, of yamaha Corp. He confirmed 
> that the stamped scale indications on the long bridge are INDEED Metric, 
> as I suspected. On the vast majority of grands, and probaly uprights as 
> well, "Suzuki" wire, which is metric sized, is used. Bottom line from 
> Yamaha: When restringing with American Standard wire,  use 1/2 size 
> smaller than indicated on the bridge. Simple enough.
>
> Terry Peterson

    To pick nits, I argue that those numbers aren't really "metric;" 
they're just a different way of expressing wire sizes.  "Our" numbers such 
as 13, 13 1/2, 14, 14 1/2, etc. don't really mean anything in terms of the 
English system of measurement (inches, feet, yards), except that each size 
increases by a thousandth of an inch up to size 23 or so.  You have to 
multiply by two and add five to get the diameter in thousandths of an inch.
    And with those Yamaha numbers, they're not millimeters or micro- or 
nanometers;  they're just gauge numbers.  To get the measurement in 
millimeters, you'd have to come up with some formula.  Take the customary 
(non-metric) #14 wire, which is 0.033 inches diameter:  in the metric 
system, that's approximately 0.84 millimeters, or 0.084 centimeters, or 8.4 
micrometers or 84 nanometers -- there are no metric units of measurement 
that 13.5 or 14 or 14.5 would fit.  They might as well be size 1, 1 1/2,
2, 2 1/2, etc.,  or  A, Aa, B, Bb, C, Cc, etc. or whatever.
    But it's good to know that one uses a half size smaller than the 
"metric" size stamped on the bridge.  A micrometer (the measuring tool, not 
a millionth of a meter) will help remove any doubt.
    --David Nereson, RPT