Yup. That assertion was what got me to read this thread.

What I do know, is you could buy aftermarket nuts that are (were) steel lock nuts (squashed) with a shiny copper plating. I bought them for exhaust manifold studs, and later saw them listed for the M10 manifold-to-headpipe studs.

Don't know if Volvo dealers sold them -- never saw one from them nor on a car, of which some of mine were dealer maintained when I got them.

Steel nuts clad with copper. That's what you see in the little bag (from FCP) in the corner of this pic. The copper eventually disappears, but I think at a slower rate than the steel did, in the presence of lots of heat. The steel flanged nut is what Volvo sent me. As for the M10 nuts on the head pipe, so far I've always been able to re-use the old ones. They take a 15mm socket on my cars. Brrrrap.



--
Art Benstein near Baltimore

Always a wealth of what?