| LBLiebovich Brothers INC | Rockford | IL | — | ◇ UNVERIFIED |
| LSLincoln Steel Corporation | Lincoln | NE | — | ◇ UNVERIFIED |
| LTLindsay Trnsprtn Solutions INC | Omaha | NE | — | ◇ UNVERIFIED |
 Lippert Components, INC | Goshen | IN | — | ◇ UNVERIFIED |
| Lippert Components Plant 084 | Nampa | ID | — | ◇ UNVERIFIED |
| Lippert Components Plant 151 | Kendallville | IN | — | ◇ UNVERIFIED |
| LWLittle Washington Fabrications, INC. | Christiana | PA | — | ◇ UNVERIFIED |
| LIL&n Industries INC | Rushville | IL | — | ◇ UNVERIFIED |
| LELobdell Emery Mfg CO | Alma | MI | — | ◇ UNVERIFIED |
| MMMachined Metals Mfg INC | Collegeville | PA | — | ◇ UNVERIFIED |
| MHMack Hils, INC. | Moberly | MO | — | ◇ UNVERIFIED |
| MIMadison INC / 8500 New Sapulpa Rd | Tulsa | OK | — | ◇ UNVERIFIED |
| MIMadison Industries | Los Angeles | CA | — | ◇ UNVERIFIED |
| MPMagga Products Company INC | Holly Hill | FL | — | ◇ UNVERIFIED |
| MMMagnuson Metals Utah, LLC | Salt Lake City | UT | — | ◇ UNVERIFIED |
| MSManitex Sabre INC | Knox | IN | — | ◇ UNVERIFIED |
| MAMarine Accessories Corporation (mac) | Maryville | TN | — | ◇ UNVERIFIED |
| MSMarion Steel Fabrication Incorporated | Marion | IN | — | ◇ UNVERIFIED |
| MIMaritime International INC | Broussard | LA | — | ◇ UNVERIFIED |
| MCMarley Cooling Tower Company | Louisville | KY | — | ◇ UNVERIFIED |
| MSMarshall Steel Services INC. | Arvada | CO | — | ◇ UNVERIFIED |
| MSMartin Steel INC | Huntington | WV | — | ◇ UNVERIFIED |
| MWMazzella Welding & Fabrication INC | Wellsburg | WV | — | ◇ UNVERIFIED |
| MAMcabee Assembly Facility | Tuscaloosa | AL | — | ◇ UNVERIFIED |
| MSMcb Steel, INC. | Bessemer | AL | — | ◇ UNVERIFIED |
| MIMcdermott INC | Gibson | LA | — | ◇ UNVERIFIED |
| MIMcdermott INC - Morgan City Fabrication Facility - Amelia Yard | Amelia | LA | — | ◇ UNVERIFIED |
| MTMce Technologies INC | Seattle | WA | — | ◇ UNVERIFIED |
 Mclaughlin Body CO | East Moline | IL | — | ◇ UNVERIFIED |
| MSMcneely Steel & Supply | Leavenworth | KS | — | ◇ UNVERIFIED |
| MIMct Industries Inc, Government Manufacturing | Bernalillo | NM | — | ◇ UNVERIFIED |
| MOMetalcraft of Mayville | West Bend | WI | — | ◇ UNVERIFIED |
| MIMetal Industries, INC | Crystal River | FL | — | ◇ UNVERIFIED |
| MPMetal Pros | Wichita | KS | — | ◇ UNVERIFIED |
| MPMetals & Plastics INC | Longwood | FL | — | ◇ UNVERIFIED |
| MSMetropolitan Steel I/steelco | Sinking Spring | PA | — | ◇ UNVERIFIED |
| MMMetso Minerals | Milwaukee | WI | — | ◇ UNVERIFIED |
| MUMeyer Utility Structures | Clinton | IL | — | ◇ UNVERIFIED |
| MAMid America Steel Inc-fargo | Fargo | ND | — | ◇ UNVERIFIED |
| MCMid-continent Coal & Coke | Portage | IN | — | ◇ UNVERIFIED |
| MAMiddle Atlantic Products, INC. | Fairfield | NJ | — | ◇ UNVERIFIED |
| MIMid-park INC - Mid-park Highway | Leitchfield | KY | — | ◇ UNVERIFIED |
| MSMid States Steel Products CO | Lexington | KY | — | ◇ UNVERIFIED |
| MSMidstate Steel, INC. | Macon | GA | — | ◇ UNVERIFIED |
| MMMidwest Machine Products INC | Golden | CO | — | ◇ UNVERIFIED |
| MIMiller/greeneville INC. | Greeneville | TN | — | ◇ UNVERIFIED |
| MFMillers Fab & Weld Corporation | Riverside | CA | — | ◇ UNVERIFIED |
| MFMillinocket Fabrication & Machine INC | Millinocket | ME | — | ◇ UNVERIFIED |
 Mills Manufacturing INC | Earlville | IA | — | ◇ UNVERIFIED |
| MRMiltec Resources Uss Edgar Thomson Works | Braddock | PA | — | ◇ UNVERIFIED |
