You can also get new hardware through them or just remove one of the nuts and bolts to take them into your local hardware store. You do not have to have a specific bolt. Someone working in the store should be able to point you to a matching nut/bolt combo.
Max, please don't listen to this advise above. I just refinished my Watanabe 2 piece wheels and there's no way I would use hardware store bolts/nuts on my wheels. Reason is that unless you're going to a really well stocked hardware store they'll likely not have high strength bolts needed for an automotive application. And I definitely wouldn't trust a store employee for knowing the difference...trust me I know first hand. Most of the stuff at a regular hardware store is for general purpose not for a wheel supporting the full weight of a moving car.
I ordered my 12.9 grade/M8x1.25/zinc plated/30mm bolts and grade 8/M8x1.25/flanged/serrated/zinc plated nuts from my local fastenal distributor. You should check out their website (http://www.fastenal.com
) to see if there's a distributor near you and you could just go in there with a sample bolt/nut to have them find them for you, just be sure to tell them what application you're using them for, or call them to be 100% sure you're ordering the right stuff. Oh and FYI, it's a little cheaper buying from them locally then ordering online. They're a little pricey but I'm glad I spend the $100 on both the nuts/bolts knowing I'm running the appropriate grade hardware. Oh and don't cheap out, get zinc coated hardware so it won't rust!