| NSNorth Shore Manufacturing | Coloma | — | ◇ UNVERIFIED |
| OOjibway | Ecorse | — | ◇ UNVERIFIED |
| OSOlympic Steel INC | Detroit | — | ◇ UNVERIFIED |
| OROttawa River Steel | Detroit | — | ◇ UNVERIFIED |
| PMPadnos Manufacturing INC | Grand Rapids | — | ◇ UNVERIFIED |
| PIPal-tec INC | Wallace | — | ◇ UNVERIFIED |
| PGPanther Global Technologies | Wixom | — | ◇ UNVERIFIED |
| PMPanther Machine INC | Wixom | — | ◇ UNVERIFIED |
| PHPicard Holding USA | Battle Creek | — | ◇ UNVERIFIED |
| PAPortage Aluminum Foundry | Galesburg | — | ◇ UNVERIFIED |
| PDPrecision Die Cast, Inc. | Kimball | — | ◇ UNVERIFIED |
| PTPrecision Tooling Technologies, LLC | Zeeland | — | ◇ UNVERIFIED |
| PTPremier Tool and Die Cast CORP | Dowagiac | — | ◇ UNVERIFIED |
 Profile Extrusion CO INC | Coldwater | — | ◇ UNVERIFIED |
| QMQDC Manufacturing | Brighton | — | ◇ UNVERIFIED |
| QNQuality Non-ferrous Foundry | Wyoming | — | ◇ UNVERIFIED |
| RNRacer-saginaw Nodular Indust | Saginaw | — | ◇ UNVERIFIED |
| RCRail Components, Inc. | Muskegon | — | ◇ UNVERIFIED |
| RTRevstone Transportation LLC | Vassar | — | ◇ UNVERIFIED |
| RTRJ Torching, Inc. | Flint | — | ◇ UNVERIFIED |
| RSRothbury Steel INC | Rothbury | — | ◇ UNVERIFIED |
| RSRouge Steel CO | Dearborn | — | ◇ UNVERIFIED |
| RTR&R Tool, Inc. | Holland | — | ◇ UNVERIFIED |
| RERyan Engineering Design | Pellston | — | ◇ UNVERIFIED |
| SHSamuel-whittar Holdings INC | Troy | — | ◇ UNVERIFIED |
| SESapa Extrusions NA | Kalamazoo | — | ◇ UNVERIFIED |
| SFSchwarb Foundry | Warren | — | ◇ UNVERIFIED |
| SISchwarb Industries INC | Troy | — | ◇ UNVERIFIED |
| SESet Enterprises INC | New Boston | — | ◇ UNVERIFIED |
| SNSeverstal North America INC | Dearborn | — | ◇ UNVERIFIED |
| SFSherwood Friction Materials | Detroit | — | ◇ UNVERIFIED |
| SSShoreline Steel Supply INC | New Haven | — | ◇ UNVERIFIED |
| SSigncomp | Grand Rapids | — | ◇ UNVERIFIED |
| SCSmith Castings INC | Kingsford | — | ◇ UNVERIFIED |
| SCSmith Castings LLC | Kingsford | — | ◇ UNVERIFIED |
| SMSteel Mill Components INC | Warren | — | ◇ UNVERIFIED |
| SFSuperb Fabricating LLC | South Lyon | — | ◇ UNVERIFIED |
| SFSuperb Fabricating LLC | New Hudson | — | ◇ UNVERIFIED |
| TSTce Systems INC | Charlotte | — | ◇ UNVERIFIED |
| TMT-four Manufacturing & Engineering, INC. | Ionia | — | ◇ UNVERIFIED |
| TPThreaded Products CO | Richmond | — | ◇ UNVERIFIED |
| TBThunder Bay Foundry | Alpena | — | ◇ UNVERIFIED |
| TCTial Cast | Owosso | — | ◇ UNVERIFIED |
| TATi Automotive (formerly Bundy Corportation) | Warren | — | ◇ UNVERIFIED |
| TGTi Group Automotive Systems LLC | Auburn Hills | — | ◇ UNVERIFIED |
| TTTrick Titanium | Holt | — | ◇ UNVERIFIED |
| TCTurbo Components INC | Spring Lake | — | ◇ UNVERIFIED |
| UAUacj Automotive-6th Street | Ludington | — | ◇ UNVERIFIED |
| UAUacj Automotive Whitehall Industries INC | Ludington | — | ◇ UNVERIFIED |
| USUnited States Steel Corporation, Great Lakes Works, Egl at Dearborn | Dearborn | — | ◇ UNVERIFIED |
