| MWMaterion - Wheatfield | Wheatfield | NY | Primary Metal Manufacturing331491 | 20-99 | ◐ LIKELY ACTIVE |
| MMbaf | Blue Island | IL | Primary Metal Manufacturing331529 | 20-99 | ◐ LIKELY ACTIVE |
| MKMB Kit Systems LLC, dba Industrial Profile Systems | Akron | OH | Primary Metal Manufacturing331318 | 20-99 | ◐ LIKELY ACTIVE |
| MMct | Sallisaw | OK | Primary Metal Manufacturing331523 | 20-99 | ◐ LIKELY ACTIVE |
| MSMedtronic Santa Clara | Santa Clara | CA | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| MMMemphis Mill Service Company | Memphis | TN | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| MMMetal Management Midwest, Inc (dba Sims Precious Metals) | Franklin Park | IL | Primary Metal Manufacturing331492 | 20-99 | ◐ LIKELY ACTIVE |
| MLMetal-Matic, LLC Middletown Plant | Middletown | OH | Primary Metal Manufacturing331210 | 20-99 | ◐ LIKELY ACTIVE |
| MSMetal Source, LLC (GHR01) | Wabash | IN | Primary Metal Manufacturing331314 | 20-99 | ◐ LIKELY ACTIVE |
| MSMetal Source, LLC (GHR11) | Scottsboro | AL | Primary Metal Manufacturing331314 | 20-99 | ◐ LIKELY ACTIVE |
| MUMetals USA- Wooster | Wooster | OH | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| MSMillennium Steel Service | Princeton | IN | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| MMMI Metals - Prescott Valley | Prescott Valley | AZ | Primary Metal Manufacturing331318 | 20-99 | ◐ LIKELY ACTIVE |
| MMinneapolis | Minneapolis | MN | Petroleum and Coal Products Manufacturing324122 | 20-99 | ◐ LIKELY ACTIVE |
| MIMinteq International | Canaan | CT | Primary Metal Manufacturing331491 | 20-99 | ◐ LIKELY ACTIVE |
| MMMisa Metal Processing Louisville, Kentucky | Louisville | KY | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| MMMisa Metal Processing Portland, Tennessee | Portland | TN | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| MAMMA Aero | Terrell | TX | Primary Metal Manufacturing331492 | 20-99 | ◐ LIKELY ACTIVE |
| MMModern Manufacturing International | Wausau | WI | Primary Metal Manufacturing331210 | 20-99 | ◐ LIKELY ACTIVE |
| MMMonarch Materials Group, Inc. | Adel | IA | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| MSMonarch Steel Company, Inc. | Cleveland | OH | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| MSMonarch Steel of Alabama, Inc. | Decatur | AL | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| MCMoody Construction Services, Inc. | Duette | FL | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| MMMOVA Metals - Freeport | Freeport | TX | Primary Metal Manufacturing331492 | 20-99 | ◐ LIKELY ACTIVE |
| MUMPG US Kent | Kent | WA | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| NNARSTCO-Midlothian | Midlothian | TX | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| NHNCSP Holdco, LLC | New Castle | IN | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| NSNelsen Steel Company | Franklin Park | IL | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| NSNelson Steel Products Inc. | Hatfield | PA | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| NWNelson Wire & Steel | New Salem | PA | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| NBNew Boston Division | New Boston | OH | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| NONFCA Operations LLC -Norton Shores | Norton Shores | MI | Primary Metal Manufacturing331529 | 20-99 | ◐ LIKELY ACTIVE |
| NLNiagara LaSalle Corporation | Warren | MI | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| NLNiagara LaSalle - South Holland Plant | South Holland | IL | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| NHNight Hawk | Fort Wayne | IN | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| NZNiles Zekelman Industries | Niles | OH | Primary Metal Manufacturing331210 | 20-99 | ◐ LIKELY ACTIVE |
| NINorthern Iron LLC | St Paul | MN | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| NINorthern Iron LLC | Saint Paul | MN | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| NCNucor Cold Finish | Brigham City | UT | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| NSNucor Skyline | Belpre | OH | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| NSNucor Skyline | Camp Hill | PA | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| NInVent ILSCO | Greenville | PA | Primary Metal Manufacturing331318 | 20-99 | ◐ LIKELY ACTIVE |
| OSOhio-Kentucky Steel, LLC | Toledo | OH | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| OAO&k American - Chicago Plant | Chicago | IL | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| OAO&k American - Seymour Plant | Seymour | IN | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| OBOldcastle Building Envelope Service Center | Charlotte | NC | Primary Metal Manufacturing331313 | 20-99 | ◐ LIKELY ACTIVE |
| OOPTA-Affival | New Kensington | PA | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| OKO.S. Kelly Company | Springfield | OH | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| ODOzark Die Casting | St Clair | MO | Primary Metal Manufacturing331523 | 20-99 | ◐ LIKELY ACTIVE |
| ODOzark Die Casting | Saint Clair | MO | Primary Metal Manufacturing331523 | 20-99 | ◐ LIKELY ACTIVE |