They are just normal non fancy bolts you can "buy them by the pound" at farm and fleet. There are a few that are short make sure you get those figured out: you can drive a long screw in until it bottoms to determine which holes are deep or shallow.
I would get grade five. The torque on M6 is normally 10 Nm or 7 ft·lb use a tool stretch a bolt make a leak.
__________________
2011 E70 • N55 (me)
2012 E70 • N63 (wife)
|