__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Regardless of what country or standards you are working to no I wouldn't use copper bolts and nuts for a bolted copper busbar connection over, say two different grades of stainless steel nuts and bolts (for strength of bolted connection and to prevent binding), that's just plain silly.