In article
,
Smitty Two wrote:

In article ,
"Michael A. Terrell" wrote:

Smitty Two wrote:

Yes there are many alloys of solder. 60/40 was the standard for some
time but was replaced 20 years ago by 63/37. That is the only tin/lead
ratio that is eutectic and has been the industry standard for all
soldering AFAIK, for at least 20 years. You may have used 80/20 for some
reason, but it certainly isn't eutectic.


I never claimed that it was.

Well, you wrote:

"80/20 is used for wave soldering, because it has a very narrow
temperature range where it is in a plastic state. this reduces cold
solder joints, by not giving the leads a chance to move while the solder
passes through this state."



If that isn't the definition of eutectic, than you have my apology for
being wrong yet again.

Defintion of eutectic:

"The lowest temperature at which a mix of two materials will melt. Often
the temperature is an anomaly, that is, it is much lower than the
melting temperatures of only slightly different mixtures. Lead-tin
solder is an example. Lead melts at 327C, tin at 231C. The lowest
melting combination is 67 lead, 33 tin (180C). Non-eutectic mixtures
have a melting or softening range. Such mixtures do not flow well until
thoroughly heated past the softening range."

Jeesh, get a dictionary.

Al