Which is stronger: a fine-thread bolt or a coarse-thread bolt?

I'm adding a spray rig to the back of a Polaris ATV quad bike, and i'd like to know: which one is a stronger bond? fine-thread or coarse-thread? i have both, so it's a toss-up.

anyone know? a web link would be appreciated, too.

Thanks,
-Snow
3 answers 3