rayell

Well; the above is the high dollar way, but if you don't care if they are used go junkyarding. Most under the hood bolts are 5/16"x1" with SAE (fine) threads, though some are 1 1/4" inches long. They do not have to be hardened on sheetmetal. I buy mine at an industrial fastener supply store in my localityIf you don't have such a store, go to a hardware store and buy hex head bolts and use a washer.

On my car I opted to use S/S bolts and washers for looks, and to avoid them rusting.

An industrial fastener store will have the correct size carriage bolts, nuts and washers in stainless for the bumpers. If you want the chrome covered cap bolts they will have to be bought from one of the high dollar auto parts suppliers.

If you don't have the inner fender slip on nuts, use nuts, flat washers, with lock washers.

No one will be looking under the fender to see what type nuts hold the fender on.