Piano wire tensile strength

[Dave McKibben]

> [Original Message]
> From: Delwin D Fandrich <fandrich@pianobuilders.com>
> To: Pianotech <pianotech@ptg.org>
> Date: 6/25/2005 4:10:14 PM
> Subject: RE: Piano wire tensile strength

>I agree with Ron N.
I worked in a stress / strain lab for 7 years and did all the testing, and
while I'm not an engineer, we did work together.
Twisting will put a torsional stress component in the wire, and if you pull
it in tension it would be my experience that it would break sooner.
Twisting is a Torsional ( torque ) stress component, and axial pulling is a
Tensile stress.  Steel wire, given the way it is made and the imperfections
in it, will have an average TENSILE STRENGTH, but twisting or pulling will
not increase the base Tensile Strength, but it will impart a STRESS.
my 2 cents for what it's worth
Dave M.
>  
>
> | -----Original Message-----
> | From: pianotech-bounces@ptg.org 
> | [mailto:pianotech-bounces@ptg.org] On Behalf Of Ron Nossaman
> | Sent: June 25, 2005 2:41 PM
> | To: Pianotech
> | Subject: Re: Piano wire tensile strength
> | 
> | 
> | No, bells are different. Twisting them just breaks 'em. I'm 
> | no metallurgist, but it will certainly increase tensile 
> | STRESS. I don't see how it could possibly increase tensile 
> | STRENGTH. Perhaps it seemed to increase tensile strength 
> | because the twisted wire didn't stretch as far under tension 
> | as an un-twisted wire. Rats! Another thing on the R&D list to 
> | test some day. Otherwise, it sounds like yet another of those 
> | old revered truths that everyone accepts as fact until 
> | someone actually tries to rationally and scientifically verify it.
> | 
> | Maybe helps, maybe not - depending.
> | 
> | Ron N
> | _______________________________________________
>
> Nope. Doesn't help at all. Well, I do now know why my bells have been
breaking.
>
> Del
>
>