I doubt you will find the proper bolt at a hardware store, maybe a auto-zone or NAPA. BUT what I would do is look in the yellow pages for a fastner distributor in your area. I found one a little over an hour away and they carry everything you would ever need as far as metric hardware goes, every grade, SS and nickle coated hardware, flanged bolts, studs, safety wire drilled grade8 bolts, even hard to find BSPT fittings and adaptors. I make a trip every now and then and sorta stock up while browsing the aisles like a kid in a candy store,,,Love that SS and nickle coated stuff!