Bridge Pins, was Bridge Capping Materials: Ebony?

[Dean May]

>>In other words, the smaller the hardness number the harder the steel. 

Ooops. That's backwards. A softer material will have a bigger diameter
dent and a smaller hardness number. A harder material will have a
smaller dent and a bigger hardness number. 

I am suspect of the numbers you are quoting, Ron. The little research
I'm doing shows Vickers hardness of mild steel at 140, Hardened steel at
900, and titanium at 970. 

Then on an ask the experts site someone asked the hardness ranking of
various metals. Here is the answer:

In General- and I have to qualify that by saying I'm considering the
metals to be in the annealed condition, the aluminum is 1100 alloy, the
T6 (not annealed, but age hardened) aluminum is a 2000 or 7000 series
alloy, and the titanium is 6Al-4V alloy rather than the commercially
pure stuff (6-4 is a lot more common than CP)- the order would be
aluminum, brass, bronze, T6 aluminum, mild steel, stainless steel, and
titanium. If the metals are in their hardest conditions, from heat
treating or cold work, the order would be aluminum, brass, T6 aluminum,
bronze, titanium, mild steel, and stainless steel (cutlery grades).
(http://experts.about.com/q/2280/1021526.htm)






Dean
Dean May             cell 812.239.3359
PianoRebuilders.com   812.235.5272
Terre Haute IN  47802


-----Original Message-----
From: Dean May [mailto:deanmay@pianorebuilders.com] 
Sent: Friday, December 02, 2005 8:29 PM
To: 'Pianotech'
Subject: RE: Bridge Pins, was Bridge Capping Materials: Ebony?

Hardness in steel is tested by machines that try to put a dent in it.
The bigger the dent, the softer the steel. The hardness number given is
inversely proportional to the diameter of the dent left in the steel. 

Check out http://www.gordonengland.co.uk/hardness/vickers.htm 

Dean
Dean May             cell 812.239.3359
PianoRebuilders.com   812.235.5272
Terre Haute IN  47802


-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On
Behalf Of Ron Nossaman
Sent: Friday, December 02, 2005 5:41 PM
To: Pianotech
Subject: Re: Bridge Pins, was Bridge Capping Materials: Ebony?


> Titanium probably does resist grooving better that what is 
> usually used for bridge pins. 

I find a Vickers hardness of 60 for titanium, and 98 for mild steel. 
Why would titanium "probably" resist grooving better when it's a 
softer material?


> I've thought about stainless, is it 
> harder than what we usually use?  Any other improvements to consider?

Go here.
http://www.matweb.com/search/search.asp
Prospect to your heart's content.

Ron N
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