I finally got the new Megastep side-steps (made by Louverne) which install using the existing mounting bolts under the body/frame. The problem is (and I kind of feel stupid for asking ), but I'm not sure if these bolts are metric or what
I can't seem to find a socket that actually fits these bolts, so that I can undo them to install the brackets.
I'm sure somebody else has done this already and may be could tell me what size socket is the right one to use. I don't want to ruin the bolts as they are very tight and if I use the wrong sockets they'll end up getting chewed up, but none of the standard sockets I have seem to fit right.
Thanks for the help.

 

most everything is metric.....