mounting a derailleur adapter claw
So I have a couple of old frames I'd like to hang more modern rear derailleurs on. One bike I just got the frame, which lacks a derailleur hanger, and the other has a cheap RD that has a claw as part of it. I went to the LBS and asked for adapter claws. At first they didn't know what I was talking about but eventually dug some out of a drawer (after telling me I should just go buy another cheap RD instead because it'd come with one as part of it). So when I got home, I realized they didn't give me the bolts that you use to keep them in the dropout.
Are these a standard size that I can pick up at a hardware store (along with a washer and a nut to keep in place), or are they something special for this part? I thought I read something somewhere about the nut being special to fit into the dropout partially? Though I could have dreamed that.