[CAUT] Breaking strengths / percents

[Ric Brekne]

Hi folks

I'm looking at how to compensate for use of pure sound wire in 
spreadsheets for calculating scales.  I have the Tension bit figured 
out, but I am unsure of how to deal with breaking tension and % of that.

Roberts gives a simple 0.557*d^1.667  (d in mils) and result in lbs.

This is for steel wire with an average density of 7.85 gm /cm^3 and an E 
modulus of 192 kN/mm2

Pure sound has an average density of 7.87 and an E modulus of 187.5

What I need to know is what the formula for % breaking strength for pure 
sound is.

Any help to get out there ?

Cheers
RicB