| NANanshan America Advanced Aluminum Technologies | Lafayette | — | ◇ UNVERIFIED |
| NSNational Standard Company | Mishawaka | — | ◇ UNVERIFIED |
| NLNiagara Lasalle Corporation | Hammond | — | ◇ UNVERIFIED |
| NTNucor Tubular Products | Madison | — | ◇ UNVERIFIED |
| OVOhio Valley Aluminum CO. LLC | Boonville | — | ◇ UNVERIFIED |
| OBOldcastle Building Envelope | New Augusta | — | ◇ UNVERIFIED |
| OGOld Guard Industrial Group, LLC | Indianapolis | — | ◇ UNVERIFIED |
| OMOmco Midwest Roll Forming | Pierceton | — | ◇ UNVERIFIED |
| PSPhoenix Services LLC Pig Iron Caster | Gary | — | ◇ UNVERIFIED |
| RLRubiconusa LLC | Bedford | — | ◇ UNVERIFIED |
| SIScepter INC (landfill) | Bruceville | — | ◇ UNVERIFIED |
| SSService Steel Framing, Inc. | Auburn | — | ◇ UNVERIFIED |
| STSeymour Tubing Incorporated | Seymour | — | ◇ UNVERIFIED |
| SAShipston Aluminum Technologies Incorporated | Franklin | — | ◇ UNVERIFIED |
| SMSms Mill Services LLC Contractor of Ace | Burns Harbor | — | ◇ UNVERIFIED |
| SCSouthwire Company LLC | Bremen | — | ◇ UNVERIFIED |
| SCSouthwire Company LLC | Lafayette | — | ◇ UNVERIFIED |
| SISrt Investments | Wabash | — | ◇ UNVERIFIED |
| SDSteel Dynamics, INC. | Pittsboro | — | ◇ UNVERIFIED |
| SDSteel Dynamics, INC. (sdi), Structural | Columbia City | — | ◇ UNVERIFIED |
| SDSteel Dynamics INC Structural & Rail Division | Columbia City | — | ◇ UNVERIFIED |
| SCStone City Ironworks INC | Bedford | — | ◇ UNVERIFIED |
| SIStripco, INC. | Mishawaka | — | ◇ UNVERIFIED |
| SESuncoke Energy | Wheatfield | — | ◇ UNVERIFIED |
| TEThormax Enterprises, LLC | Columbus | — | ◇ UNVERIFIED |
| TEThormax Enterprises, LLC | Columbus | — | ◇ UNVERIFIED |
| TUTokusen USA Incorporated | Little York | — | ◇ UNVERIFIED |
| UCUss Central Teaming Company INC | Gary | — | ◇ UNVERIFIED |
| USU. S. Steel | Gary | — | ◇ UNVERIFIED |
| USUS Steel Gary Complex | Gary | — | ◇ UNVERIFIED |
| VCVibromatic Company Inc | Noblesville | — | ◇ UNVERIFIED |
| WTWabash Trucking, LLC | Wabash | — | ◇ UNVERIFIED |
| WSWaelz Sustainable Products LLC | Muncie | — | ◇ UNVERIFIED |
| WCWard Corporation | Fort Wayne | — | ◇ UNVERIFIED |
 Waupaca Foundry | Tell City | — | ◇ UNVERIFIED |
| WMWhiting Metals, LLC | Whiting | — | ◇ UNVERIFIED |
| YDYellow Dog Extrusion | Mishawaka | — | ◇ UNVERIFIED |
