This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment A potential problem with (austenitic) Stainless is that there is a = galvanic reaction with the carbon steel music wire. The stainless = eventually will corrode to some degree especially at/near the string = termination point.. Mark Ultsch Madison ----- Original Message -----=20 From: Steve Fujan=20 To: deanmay@pianorebuilders.com ; Pianotech=20 Sent: Friday, December 02, 2005 11:25 PM Subject: Re: Bridge Pins, was Bridge Capping Materials: Ebony? Hardened stainless steel gets my vote. Not only is it harder (hence = more wear resistant), it is also considerably stiffer than titanium. = The more flexible titanium would bend more right where the pin enters = the wood causing higher stress right where you don't want it. The = stainless steel would spread the force over greater depth into the = bridge.=20 Plus hardened stainless in these small diameters should be relatively = easy to make, hence cheaper, er.. less expensive than titanium. Steve Fujan (BSME, MSME, PE) www.fujanproducts.com =20 On 12/2/05, Dean May <deanmay@pianorebuilders.com> wrote:=20 >>In other words, the smaller the hardness number the harder the = steel. Ooops. That's backwards. A softer material will have a bigger = diameter=20 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=20 900, 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,=20 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=20 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?=20 > 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=20 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=20 Prospect to your heart's content. Ron N _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives=20 _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/41/d2/87/08/attachment.htm ---------------------- multipart/alternative attachment--
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