[BC] the solder I'm using

[RichardBJohnson at comcast.net]

True, but it is also the point at which no more of the second metal will dissolve in the first as Cowboy said. This is true for two metal alloys. Alloys that contain three or more metals can also be made eutectic using this method because the higher melting-point metal will precipitate out during the alloying process, leaving the exact metallic proportions necessary to provide the lowest melting point. See http://en.wikipedia.org/wiki/Rose%27s_metal Rose's metal for example.

Cheers,
Richard B. Johnson
Book: http://www.AbominableFirebug.com/

----- Original Message -----
From: "David Reaves" <rrsounds at aol.com>
Cc: "David Reaves" <rrsounds at aol.com>

IIRC, "eutectic" is the term for the exact mixture percentage of two  
or more metals that yields the lowest melting temperature. I also  
recall that, typically, the eutectic temperature can be considerably  
lower than that of either of the elements alone.

David Reaves