I had a devil of a time finding these. My local shop, Coleman Powersports of Falls Church, supplied four M6 hex/Phillips head screws and four _nearly useless_ hex nuts. When you toruqe the hex nuts gently, they rotate in the lead channel and rub a groove into the lead, preventing further tightening.
I bought a bag of 100 from Scott at Maryland Metrics. The square nuts dont' rotate! (Use them finished side UP) They are 10 mm square, same width as a hex nut, but fit better. More suited to the task. They are the thick version, in stainless.
Let me know by email to snipped-for-privacy@aol.com, Subject: M6 Square Nuts ...
if you would like some, or would like to take the remaining lot of 96 or so at a fair price.
I like to cram a cigarette butt under the nuts to keep them from falling into the works.
I don't think this would do well on ebay. Do you?
Doug Goncz Replikon Research Falls Church, VA 22044-0394 That's DGoncz (at) aol (dot) com....