In article t,
RoyJ wrote:

Don't use grease, use the appropriate version of 'Never Seize'


Seconded enthusiastically!

I work part-time as a shop tech at a Medical Supply house.

Sunrise Medical, the makers of the Quickie wheelchairs, have a bad habit
of using hardened socket-head machine screws to fasten aluminum
assemblies. After a few years, these screws can become almost impossible
to remove due to the corrosion between the steel and aluminum.

Sunrise isn't the only maker that does this, but they're the biggest
one. I've often asked their tech support folks whether their engineers
have ever heard of galvanic corrosion or metal galling.

A good demonstration of GC is to use an aluminum patch for a hole in
your car fender. DAMHIKT!

IF I _do_ manage to get them apart, when they go back together, there's
a healthy dose of Never-Sieze on the screws. I haven't yet had one of
the screws loosen, but they're easily removed the next time the chair
comes in for service.