string breakage

[fssturm@unm.edu]

Quoting Joe And Penny Goss <imatunr@srvinet.com>:

> Re: string breakageThe idea that a thinner string is stronger than a
> > thicker wire does not seem to follow the laws of physics.
> Now if you mean that a thinner wire will sound a higher note with
> less > or the same tension, then I would agree to that.
>
> "Thinner is stronger than thicker, but the improvement is minimal for
> > high carbon steel music wire". 
>
> Joe Goss

	I've written this opinion before: use a thinner string. The thicker string requires 
more tension to get to the given pitch (same string length obviously being a 
given). For those with a bent for math and physics, the mass of the string is the 
significant factor here. While thinner wire has a bit more strength per cross 
sectional area (due to the working of the wire in the drawing process), that factor 
is relatively irrelevant.
	Think of it this way: a "perfect scale" would have a single diameter wire, 
doubling length every octave. Every note would have exactly the same tension 
in this theoretical scale. So a string designed to be within breaking tension for 
the top note would work throughout - wouldn't break throughout.  But the 
resulting instrument would be far too long. 
	So we make a compromise curve that foreshortens lengths to less than 2:1 per 
octave. If we used a single diameter wire on this foreshortened scale, the 
tension would drop dramatically from top note to bottom, with resultant tone 
being awful. So, to compensate, we increase the diameter of the wire by 
increments -  so that tension will stay fairly high (a thicker diameter wire requires 
a higher tension to produce the same pitch).
	From the above, it should be obvious that, at least on a reasonably designed 
scale (not something random and haywire), the smallest diameter string will 
"work" (be well within breaking tension) throughout the scale, and that any 
smaller diameter will serve for any note - you can substitute a thinner wire for a 
thicker without fear of breakage (substitution works in terms of not breaking, not 
in terms of tone quality). Why? Because the tension will be less.
	It's a counterintuitive concept, but one which I learned many years ago from 
painful experience with a badly scaled harpsichord, and a lesson I haven't 
managed to forget since. "Try it, you'll like it" <g>
Regards,
Fred Sturm
University of New Mexico