string breaking test

[Richard Brekne]

Stéphane Collin wrote:

> Hello all.
> 
> I just made some strings breaking tests, and am a bit in trouble.
> Have that beautiful Bechstein model IV in mint condition, from 1870, with I
> believe original strings on it.
> Asked a friend (engineer) to do the breaking tests on that wire, and at the
> same time, do the same tests on modern wire.  Both tests led to this numbers
> :  1870 wire breaks at about 1500 N/mm² and modern (2000) wire (Röslau) :
> exactly the same.
> Good news : I can restring that 1870 piano with modern wire.
> Bad news : when I read Stephen Paulello papers, the numbers don't match at
> all : he says modern wire should break at something between 1800 and 2200
> N/m².
> Any comments ?
> 
> Stéphane Collin
> 

Perhaps I misunderstand... but it seems to me that 2000 N/mm^2 is 
exactly half way inbetween 1800 and 2200 N/mm^2.

Whats the give then ?

RicB


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