Single piston caliper bolts

those kits come with the bolts that hold the clips down that contain the caliper, if that's what you're talking about. i don't remember the size-- maybe 1/4-20 but they do have a captive washer that i believe is conical.

at about 12 bucks from that's pretty cheap for the correct hardware. but you could just hit up a hardware store and grab some grade 5's and knock it together with a little loctite.