Need the closest size drill bit to a rivet? Here's a good place to start:
4 gauge wire is .204" diameter - Use #6 (204") drill
6 gauge wire is .162″ diameter - Use #19 (.166") drill
8 gauge wire is .128″ diameter - Use #30 (.1285") drill
10 gauge wire is .102″ diameter - Use #37 (.104") drill
12 gauge wire is .081″ diameter - Use #46 (.081") drill
14 gauge wire is .064″ diameter - Use #51 (.067") drill
16 gauge wire is .051″ diameter - Use #55 (.052") drill
18 gauge wire is .040″ diameter - Use #58 (.042") drill
20 gauge wire is .032″ diameter - Use #65 (.035") drill