In article ,
says...
In article ,
"Joe" wrote:

We use some decent flat head screws on our units and I've run into a strange
problem. When we tighten them into the aluminum housings, they hold a
galvanized plate in place. After about 10 minutes of being on there, they
are almost impossible to get off.

If you ignore basic chemistry you're going to suffer. Your problem
description lays it out - you're plating the screw in place, for all
intents and purposes, using the very nice battery formed by the
aluminum, steel and zinc. Whoever designed this should be sent back to
their high school chemistry teacher and forced to make an apology.


No electrolyte, no battery. Aluminum would be a much less useful
material if it could never be used it with steel fasteners.

Ned Simmons