The bolt head says M 10.9 and it's about 45mm in length. I'm worried about getting just any old bolt because of the heat it's subjected to...
i am surprised they are using 10.9 there, but that's fine. that's longer than i thought though.
A4 stainless is mostly equivalent to 10.9 (A4 not A2) but you can find 10.9 or even 12.x series bolts around.
If you really want to be anal, buy some 12.8 bolts with the Dacromet coating. heat, chemical, friction, radiation, and Beezlebub resistant. might be harder to find.
Maryland Metrics has plenty of bolts of all sizes.
