no really...
I was researching parts for my car and found these guys
they are M6, 8mm nut, copper, with anti backoff crimpring.
they are made for a 88-89 e30 M3 BMW exhaust manifold
They would be perfect for thoes hard to install exhausts and other shit that always is a pain, and they wont rattle off, corrode or strip your threads!
they are about .35-55 cents a piece depending on dealer prices, and can be had at any BMW car dealership parts counter.
part number: 11621304755
the only issue is that most peeps dont carry a 8mm with them