Machina Labs, Inc Mach E | Chatsworth | CA | 20–99 | ◐ LIKELY ACTIVE |
| MWMachinery West INC | Boise | ID | — | ◐ LIKELY ACTIVE |
| MBMadden Bolt Corporation KERMIER | Hockley | TX | 100–499 | ◐ LIKELY ACTIVE |
| MMaine | Kingfield | ME | 20–99 | ◐ LIKELY ACTIVE |
| MPMainstream Packaging, Inc. | Lebanon | KY | 20–99 | ◐ LIKELY ACTIVE |
| MWMajor Wire Guada Coma | Schertz | TX | 1–19 | ◐ LIKELY ACTIVE |
| MWMajor Wire Texas | Schertz | TX | 20–99 | ◐ LIKELY ACTIVE |
| MEManufacturers Equipment CO | Middletown | OH | — | ◐ LIKELY ACTIVE |
| MManufacturing | Willis | TX | 100–499 | ◐ LIKELY ACTIVE |
| MMMarcon Metal USA Inc | Ferndale | WA | 20–99 | ◐ LIKELY ACTIVE |
| MRMasonry Reinforcing Corp of America dba Wirebond | Charlotte | NC | 100–499 | ◐ LIKELY ACTIVE |
| MEMast Enterprises Equipment LLC | South Boston | VA | — | ◐ LIKELY ACTIVE |
| MHMaterial Handling Division | Nashville | TN | 100–499 | ◐ LIKELY ACTIVE |
| MRMaxxim Rebuild Co., LLC dba Maxxim Manufacturing | Bluefield | WV | 100–499 | ◐ LIKELY ACTIVE |
| MNMaze Nails | Peru | IL | 20–99 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Baltimore) | Baltimore | MD | 20–99 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Baton Rouge, LA) | Gonzales | LA | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Carter Rd, OH) | Cleveland | OH | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Charlotte, NC) | Charlotte | NC | 20–99 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Chattanooga, TN) | Chattanooga | TN | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Cincinnati, OH) | Cincinnati | OH | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Cleveland, OH) | Cleveland | OH | 100–499 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Dallas, TX) | Dallas | TX | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Denver) | Denver | CO | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Distribution Center) | Memphis | TN | 20–99 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Dolomite) | Dolomite | AL | 20–99 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (East Chicago, IN) | East Chicago | IN | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Granite City) | Granite City | IL | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Lafayette) | Lafayette | LA | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Longview) | Longview | TX | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Memphis) | Memphis | TN | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Oklahoma City) | Oklahoma City | OK | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Pittsburgh, PA) | Cranberry Twp | PA | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (San Antonio) | San Antonio | TX | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Vancouver) | Vancouver | WA | 1–19 | ◐ LIKELY ACTIVE |
| MLMazzella Lifting Technologies (Virginia Beach, VA) | Virginia Beach | VA | 20–99 | ◐ LIKELY ACTIVE |
| MSMcCombs Steel Company - Winston | Statesville | NC | 1–19 | ◐ LIKELY ACTIVE |
| MMcEwen | Mcewen | TN | 20–99 | ◐ LIKELY ACTIVE |
| MPMcEwen Plant 2 | Mcewen | TN | 20–99 | ◐ LIKELY ACTIVE |
| MMcHard | Houston | TX | 100–499 | ◐ LIKELY ACTIVE |
| MWMckee Welding & Fabrication LLC | Beaufort | SC | — | ◐ LIKELY ACTIVE |
| MMcMinville | Rock Island | TN | 20–99 | ◐ LIKELY ACTIVE |
| MIMdj Industrial LLC | Houston | TX | — | ◐ LIKELY ACTIVE |
| MWMelvin Wrought Iron Inc - Main Shop | Ontario | CA | 20–99 | ◐ LIKELY ACTIVE |
| MFMenomonee Falls Location | Menomonee Falls | WI | 20–99 | ◐ LIKELY ACTIVE |
| MMMerchants Metals (M08-Statesville) | Statesville | NC | 20–99 | ◐ LIKELY ACTIVE |
| MCMetal City Fab, LLC | Warren | MI | 20–99 | ◐ LIKELY ACTIVE |
| MOMetalcrafters of Wayne County | Goldsboro | NC | 20–99 | ◐ LIKELY ACTIVE |
| MFMetal Fabrication LLC | Evansville | IN | 20–99 | ◐ LIKELY ACTIVE |
| MMMetal Masters of Florida Inc | Lake City | FL | 1–19 | ◐ LIKELY ACTIVE |