[JamesCH95]

Originally Posted by joek

the fact that they were grade 8 was probably the problem, hard bolts don't bend, they snap, and aren't very forgiving of shock forces, grade 6 is probably a better option and 8 more holes would weaken the sprocket pretty severely.

i've never heard of a team who have had issues with bolts snapping before, we never have that problem, but then again, we've never used traction drive, only mechanum and a couple tank drives.

Grade 6? As far as I know there are grades 2, 5, and 8. Grade 8 bolts are marked with 6 lines though, it's all very logical

Fasteners do very poorly when they're loose, regardless of grade. I would recommend using ny-lock nuts at the very least, and maybe add a split or star lock-washer. It might be an appropriate place to use a smaller fastener with a higher torque so that the fastener does not lose clamping force during operation.