Stainless bolts have the lowest strength but obviously have the best corrosion resistant. Hardened steel bolts have the greatest strength. I believe the bolts that come with the SW-Motech crash bars are self locking with a nylon liner. I would recommend using loctite on whatever bolts you choose.
If you live in a medium sized city or larger there are probably more than one commercial fastener store, hidden in an industrial park somewhere, that specializes in selling fasteners and bolts of all sizes and stocks every conceivable size bolt and fastener. Check your local yellow pages.
I brought bolts at the fastener store once to secure my handle bar switches, they cost next to nothing and looked identical to the OEM ones but rusted in a season. Conversely the dealer wanted $5 each for the OEM ones but they did not rust. Suspect just a difference in materials.
Last edited by twowheels; 05-15-2016 at 06:40 PM.