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Balance pinion from piano wire?


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Hey Freewheel, 

From what I've discovered, piano wire has too high carbon content resulting in a brittle pivot.

I dont know the quality of the blued steel sold on-line for the purpose of making pivots.

Can anyone suggest where to source a suitable steel among commonly found parts in general industry?

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I make balance staffs (and all other components) from a hardenable steel in its annealed state. Suitable rod steel would be O1 or what you'd probably find called silver steel in Australia.

https://mcjing.com.au/silver-steel-rod.html

 

Hardening and tempering is quite simple.

 

If you really want to make it from prehardened steel you can find that at watch material suppliers. My experience with it is old vintage Bergeon "blue steel" is rather uneven in hardness in the same bar, and modern assortments tend to be too soft for staff work.

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For what is worth, Cousins sells "pivot wire" which is actually hardened spring wire made in India, with a nicely decorated document listing its properties. I only tried biting it with the baby lathe and that was no problem, but can't tell how good really is for staffing use.

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I have used the  Cousins pivot wire with really good results.
Whilst on the subject of making balance staffs I now use “Tungsten carbide gravers”. They just stay sharp throughout the project but will chip if to aggressive. 
ps before anyone asks I use a diamond lap to sharpen.

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1 hour ago, nickelsilver said:

I make balance staffs (and all other components) from a hardenable steel in its annealed state. Suitable rod steel would be O1 or what you'd probably find called silver steel in Australia.

https://mcjing.com.au/silver-steel-rod.html

 

Hardening and tempering is quite simple.

 

If you really want to make it from prehardened steel you can find that at watch material suppliers. My experience with it is old vintage Bergeon "blue steel" is rather uneven in hardness in the same bar, and modern assortments tend to be too soft for staff work.

Cheers, I dont mind blueing myself.

I was going to buy from a popular on-line store but it's not worth finding out steel is crap after all the work's done.

I have lots of small lengths that I've collected with various antique purchases but scared to use it because I dont know its origin.

I'm guessing there's ways to test the steel with chemicals.

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