<HTML> <HEAD> <TITLE>Re: [CAUT] Tuning Pin Questions</TITLE> </HEAD> <BODY> Bluing is actually a chemical treatment.  The steel is immersed in a water-based chemical solution at or near the boiling point.  The hot solution promotes the chemical reaction, but it isn’t hot enough for the heat itself to do anything to the steel.  Look at <a href="http://en.wikipedia.org/wiki/Bluing_(steel)">http://en.wikipedia.org/wiki/Bluing_(steel)</a> for a good description of the process. There have been “cold blue” products on the market for some time.  Gun owners commonly use them for touch-up.  As I understand it, these products produce the same chemical reaction on the surface as hot blue, just not as effectively since they operate at room temperature.  I always figured the pin blue stuff that Schaff sells was this sort of thing, but I have never used it.  I have no clue what the heck in on the nickel/blued thread pins.  That’s a color not found in nature. Regards, Ken Z. On 7/8/08 11:40 AM, "Fred Sturm" <fssturm@unm.edu> wrote: <BLOCKQUOTE>Ah, but is that blue color on the threads of the nickel plated pins actually "bluing" or just a dye?Real bluing is a heat treatment, yes? I think we've all seen the Wurlitzer style "bluing" (a dye painted on the pins and dripping onto coils and sometimes plate), and I remember being able to purchase the stuff (probably ink). I am not convinced that tuning pins we get today are ever blued (true blued?) after threads are cut. So the treatment is only cosmetic, for the part of the pin that sticks out of the block, and doesn't affect the threads (hey, I could be wrong, but that color on those threads makes me awfully suspicious). I used to get some pins from Schaff that actually did seem to be "true blued" on the entire surface of the pin after threads were made. The threads were a bit deeper than what we get today. I don't know if those are still available. Regards, Fred Sturm University of New Mexico </BLOCKQUOTE>         fssturm@unm.edu -- Ken Zahringer, RPT University of Missouri School of Music </BODY> </HTML>