I found this reply in another thread:
Quote:
Originally Posted by Megadan
Since the studs in question are metric (M8 x 1.25) the equivalent of grade 8 (SAE) would be grade 10.9. 
On my last Hawk and the current one, I upgraded to stainless steel (A2) studs, washers, and nuts. Much like ARH, I use a double nut (main and locking) to secure the head pipe. I have never had one come loose or back out. The mid pipe mount is also crucial to prevent stud breakage (the one on the frame under the seat area). If that is loose and allows the pipe to vibrate it will put a lot of stress on the studs and increase the chance of, or lead up to, failures. I put two large flat washers on each side of the rubber in order to tighten it down enough without completely destroying the rubber in the process. |
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