| MMMandel Metals INC. | Franklin Park | IL | Primary Metal Manufacturing331312 | — | ◇ UNVERIFIED |
| MBManufacturers Brass & Aluminum Fdry INC | Blue Island | IL | Primary Metal Manufacturing331525 | — | ◇ UNVERIFIED |
| MMMayco Mfg LLC | Granite City | IL | Primary Metal Manufacturing331410 | — | ◇ UNVERIFIED |
| MDMbaf - Division of G&w Electric | Blue Island | IL | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| MMetaldyne | Niles | IL | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| MMMetal Management Midwest INC | Kankakee | IL | Primary Metal Manufacturing331423 | — | ◇ UNVERIFIED |
| MIMicro Industries INC | Rock Falls | IL | Primary Metal Manufacturing331522 | — | ◇ UNVERIFIED |
| MPMmi Products INC | Bartonville | IL | Primary Metal Manufacturing331222 | — | ◇ UNVERIFIED |
| MDModern Die Casting CORP | Chicago | IL | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| MTMorris Tick CO INC | Bloomington | IL | Primary Metal Manufacturing331315 | — | ◇ UNVERIFIED |
| NMNational Metalwares L.p. | Aurora | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| NINeblock INC | Rockford | IL | Primary Metal Manufacturing331312 | — | ◇ UNVERIFIED |
| NBNielsen & Bainbridge, LLC. | Bridgeview | IL | Plastics and Rubber Products Manufacturing326140 | — | ◇ UNVERIFIED |
| NSNorthwestern Steel and Wire | Sterling | IL | Primary Metal Manufacturing331111 | — | ◇ UNVERIFIED |
| NPNta Precision Axle CORP | Carol Stream | IL | Primary Metal Manufacturing331523 | — | ◇ UNVERIFIED |
| NTNucor Tubular Products | Bedford Park | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| OIOakley Industries INC | Niles | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| OSOakley Steel Products CO | Bellwood | IL | Primary Metal Manufacturing331111 | — | ◇ UNVERIFIED |
| OUOdermath USA INC | Naperville | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| OAOlson Aluminum Castings | Rockford | IL | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| OSOlympic Steel | Schaumburg | IL | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| OMOutboard Marine CORP. | Waukegan | IL | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| PRPechiney Rolled Products LLC | Mccook | IL | Primary Metal Manufacturing331315 | — | ◇ UNVERIFIED |
| PAPenn Aluminum | Murphysboro | IL | Primary Metal Manufacturing331316 | — | ◇ UNVERIFIED |
| PTPlymouth Tube CO | Streator | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| PMPrecious Metal Refining Svcs INC | Wauconda | IL | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| PCPrecise Castings INC | Saint Charles | IL | Primary Metal Manufacturing331521 | — | ◇ UNVERIFIED |
| PEPrecision Extrusions LLC | Bensenville | IL | Primary Metal Manufacturing331316 | — | ◇ UNVERIFIED |
| PIPrimecast, Inc.(former) | South Beloit | IL | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| RDRacer Danville Landfill | Danville | IL | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| RTRepublic Technologies International LLC | Harvey | IL | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| RMReserve Marine Terminal | Chicago | IL | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| RWRobert White | Centralia | IL | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| RFRockford Foundries | Rockford | IL | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| RSRoll Services INC | Glenwood | IL | Primary Metal Manufacturing331112 | — | ◇ UNVERIFIED |
| RTRubicon Technology | Batavia | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| SCSandwich Casting & Machine/trio Foundry INC | Montgomery | IL | Primary Metal Manufacturing331529 | — | ◇ UNVERIFIED |
| SISandwich Iron Foundry | Plano | IL | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| SESapa Extrusions INC | Morris | IL | Primary Metal Manufacturing331316 | — | ◇ UNVERIFIED |
| SRSims Recycling Solutions | West Chicago | IL | Primary Metal Manufacturing331314 | — | ◇ UNVERIFIED |
| SSSkyline Steel | Newton | IL | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| SLSlater Lemont CORP | Lemont | IL | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| SASmall Assemblies INC | Chicago | IL | Primary Metal Manufacturing331523 | — | ◇ UNVERIFIED |
| SISpecialloy INC | Chicago | IL | Primary Metal Manufacturing331420 | — | ◇ UNVERIFIED |
| SLState Line Foundries INC | Roscoe | IL | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| SWSteel Warehouse of Quad Cities | Rock Island | IL | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| SSSterling Steel Foundry | Sauget | IL | Primary Metal Manufacturing331513 | — | ◇ UNVERIFIED |
| TOTherm O Link INC | Morris | IL | Primary Metal Manufacturing331420 | — | ◇ UNVERIFIED |
| TSThompson Steel CO INC | Franklin Park | IL | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| TKTool King INC | Wheeling | IL | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
