 Mayville Engineering Company INC Dba Mec | Vanderbilt | MI | — | ◇ UNVERIFIED |
| MWMazzella Welding & Fabrication INC | Wellsburg | WV | — | ◇ UNVERIFIED |
| MEMbm Enterprises, INC. | Pleasant Plains | AR | — | ◇ UNVERIFIED |
| MSM.b. Sturgis INC. | Maryland Heights | MO | — | ◇ UNVERIFIED |
| MAMcabee Assembly Facility | Tuscaloosa | AL | — | ◇ UNVERIFIED |
| MWMcbrides Welding Dba American Iron | Ridgecrest | CA | — | ◇ UNVERIFIED |
| MSMcb Steel, INC. | Bessemer | AL | — | ◇ UNVERIFIED |
| MIMcdermott INC | Gibson | LA | — | ◇ UNVERIFIED |
| MIMcdermott INC - Morgan City Fabrication Facility - Amelia Yard | Amelia | LA | — | ◇ UNVERIFIED |
| MMMcdonough Marine Service | Metairie | LA | — | ◇ UNVERIFIED |
| MMMcelroy Metal Mill INC | Monroe | LA | — | ◇ UNVERIFIED |
| MMMcelroy Metal Mill INC Dba Mcelroy Metal | Adelanto | CA | — | ◇ UNVERIFIED |
| MTMce Technologies INC | Seattle | WA | — | ◇ UNVERIFIED |
| MMMcfarlane Mfg CO | Sauk City | WI | — | ◇ UNVERIFIED |
| MIMcgregor Ind Inc/dunmore Plt | Dunmore | PA | — | ◇ UNVERIFIED |
 Mclaughlin Body CO | East Moline | IL | — | ◇ UNVERIFIED |
| MFMcm Fabricators, INC. Dba Global Fabricators | Shafter | CA | — | ◇ UNVERIFIED |
| MSMcneely Steel & Supply | Leavenworth | KS | — | ◇ UNVERIFIED |
| MCMcnichols Company | Garland | TX | — | ◇ UNVERIFIED |
| MIMcReynolds Investments LLC | Waterford | WI | — | ◇ UNVERIFIED |
| MCMDI Corporation | Cheney | KS | — | ◇ UNVERIFIED |
| MCMDI Corporation | Cheney | KS | — | ◇ UNVERIFIED |
 Meadow-burke Products | Hazleton | PA | — | ◇ UNVERIFIED |
| MAMechanical and Industrial Steel Services, INC. | Channahon | IL | — | ◇ UNVERIFIED |
| MHMedway Hall Development Group, Inc. | Jacksonville | FL | — | ◇ UNVERIFIED |
| MAMeggitt Aircraft Braking Systems CORP | Danville | KY | — | ◇ UNVERIFIED |
| MPMellies Products INC. | Morganville | KS | — | ◇ UNVERIFIED |
| MSMemphis Sheet Metal Works INC | Memphis | TN | — | ◇ UNVERIFIED |
| MMMenard Manufacturing INC. | Dewitt | AR | — | ◇ UNVERIFIED |
| MMMenator Metal Works LLC | Winneconne | WI | — | ◇ UNVERIFIED |
| MCMere Capital, LLC dba Czar Weld | House Springs | MO | — | ◇ UNVERIFIED |
| MSMeridian Specialty Vehicles | Las Vegas | NV | — | ◇ UNVERIFIED |
| MFMerrill Fab | Merrill | WI | — | ◇ UNVERIFIED |
| MSMerrill Steel Camanche | Camanche | IA | — | ◇ UNVERIFIED |
| MVMesilla Valley Metals | Las Cruces | NM | — | ◇ UNVERIFIED |
| MLMetalbuilt LLC | Macomb | MI | — | ◇ UNVERIFIED |
| MIMetal-con, INC. | Sylvania | GA | — | ◇ UNVERIFIED |
| MCMetal Container Corporation | Oklahoma City | OK | — | ◇ UNVERIFIED |
| MDMetal Design Corporation | Madison | WI | — | ◇ UNVERIFIED |
| MEMetal Enterprises, INC. | Portland | OR | — | ◇ UNVERIFIED |
| MAMetalfab Arizona L.l.c. | Phoenix | AZ | — | ◇ UNVERIFIED |
| MIMetalfab INC | Kennewick | WA | — | ◇ UNVERIFIED |
| MIMetalfab INC | Richland | WA | — | ◇ UNVERIFIED |
| MFMetal Fabrication Technologies D/b/a Gerdau Ameris | Johnson City | TN | — | ◇ UNVERIFIED |
| MFMetal Fabricators, LLC | Tallahassee | FL | — | ◇ UNVERIFIED |
| MFMetal Fabricators of St Louis | Saint Louis | MO | — | ◇ UNVERIFIED |
| MFMetal for Electronics LLC | Memphis | TN | — | ◇ UNVERIFIED |
| MIMetal Industries, INC | Crystal River | FL | — | ◇ UNVERIFIED |
| MKMetal Kings | Lynwood | CA | — | ◇ UNVERIFIED |
| MMMetal Magic, LLC | Ocala | FL | — | ◇ UNVERIFIED |
