# Brass, hardness.



## MIGNAL (4 Jun 2015)

Hello,

I'm looking for a type of brass to fit a specific requirement. Thin strip brass at 0.7 (or 0.8 mm's) x 3 or 4 mm's, in small lengths. 
It's for the restoration of an old Guitar like instrument that was made around the 1750's. The brass is for the frets. Given that the strings are brass/steel I guess that it needs to be a fairly hard type of brass. The original frets are NOT the Nickel Silver alloy (white brass?) of modern fret wire. It's almost certainly softer.
I have found brass strip on Ebay given as CZ 108. Is this considered hard, as brass goes?


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## Cheshirechappie (5 Jun 2015)

CZ108 is 'forming brass' usually supplied half-hard. A trick used by clockmakers is to work-harden it by hammering until it springs rather than bends. At that point, it's about as hard as it'll get. CZ108 can be bought in sheet form in a graet variety of thicknesses; a bit of rummaging around the net revealed very few suppliers of strip, and most flats seem to start at about 1.5mm/1/16".


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## Normancb (5 Jun 2015)

You could try a search for brass boiler banding. Sold by many model engineering suppliers in all sorts of sizes. I'm not sure what grade it is.


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## profchris (14 Jun 2015)

A friend of mine uses eBay brass strip for bar frets on ukes, but these are nylon strings so hardness is pretty irrelevant. 

Would the filing needed to level and crown theses frets be enough to work harden the surface I wonder? Regulars here should know - the process is just filing the strip down to height, then producing a curve on top and polishing the upper surface.


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## CHJ (14 Jun 2015)

Phosphor bronze can be used for spring applications as supplied, no need to work harden it, it looks like brass if polished.

I'm of no help in finding a UK source of suitable sheet material I'm afraid.


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## Andrewf (15 Jun 2015)

If you look on www.model-engineer.co.uk there are loads of suppliers of all sorts and shapes of metal. Even join the forum and ask where to get it.


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