| MIMattessich Iron, LLC | Memphis | NY | — | ◇ UNVERIFIED |
| MBMaura Buildings, Incorporated | Lebanon | PA | — | ◇ UNVERIFIED |
| MMMaurice Mesple Dba Mesples Machine Shop and Pump | Fresno | CA | — | ◇ UNVERIFIED |
| MIMayco Intl LLC | Sterling Heights | MI | — | ◇ UNVERIFIED |
| MSMay Specialty Fabricators, INC. | Register | GA | — | ◇ UNVERIFIED |
 Mayville Engineering Company INC Dba Mec | Vanderbilt | MI | — | ◇ UNVERIFIED |
| MEMbm Enterprises, INC. | Pleasant Plains | AR | — | ◇ UNVERIFIED |
| MBM B Steel CO INC | Madison | IL | — | ◇ UNVERIFIED |
| MWMcbrides Welding Dba American Iron | Ridgecrest | CA | — | ◇ UNVERIFIED |
| MMMcdonough Marine Service | Metairie | LA | — | ◇ UNVERIFIED |
| MMMcelroy Metal Mill INC | Monroe | LA | — | ◇ UNVERIFIED |
| MMMcelroy Metal Mill INC Dba Mcelroy Metal | Adelanto | CA | — | ◇ UNVERIFIED |
| MMMcfarlane Mfg CO | Sauk City | WI | — | ◇ UNVERIFIED |
| MFMcm Fabricators, INC. Dba Global Fabricators | Shafter | CA | — | ◇ UNVERIFIED |
| MCMcnichols Company | Garland | TX | — | ◇ UNVERIFIED |
| MIMcReynolds Investments LLC | Waterford | WI | — | ◇ UNVERIFIED |
| MCMDI Corporation | Cheney | KS | — | ◇ UNVERIFIED |
| MCMDI Corporation | Cheney | KS | — | ◇ UNVERIFIED |
 Meadow Burke | Converse | TX | — | ◇ UNVERIFIED |
| Meadow Burke, LLC | Hazleton | PA | — | ◇ UNVERIFIED |
| Meadow-burke Products | Hazleton | PA | — | ◇ UNVERIFIED |
| MAMechanical and Industrial Steel Services, INC. | Channahon | IL | — | ◇ UNVERIFIED |
| MHMedway Hall Development Group, Inc. | Jacksonville | FL | — | ◇ 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 |
| MMMerchants Metals INC | New Paris | IN | — | ◇ 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 |
| MKMetal Kings | Lynwood | CA | — | ◇ UNVERIFIED |
| MMMetal Magic, LLC | Ocala | FL | — | ◇ UNVERIFIED |
 Metal Master LLC | Tacoma | WA | — | ◇ UNVERIFIED |
| MMMetal Masters, INC. | Mitchellville | IA | — | ◇ UNVERIFIED |
| MPMetal Parts Fabrication | Vidor | TX | — | ◇ UNVERIFIED |
| MPMetal Pros, LLC | Wichita | KS | — | ◇ UNVERIFIED |
 Metal Solutions Design & Fabrication LLC | Florence | KY | — | ◇ UNVERIFIED |
| MSMetal Specialist, INC. | Austell | GA | — | ◇ UNVERIFIED |
| MUMetals USA | Fort Washington | PA | — | ◇ UNVERIFIED |
| MMetaltek | Lakeland | FL | — | ◇ UNVERIFIED |
| MIMetal-tek, INC. | Lakeland | FL | — | ◇ UNVERIFIED |
| MWMetal & Wire Products South Carolina LLC | Ridgeway | SC | — | ◇ UNVERIFIED |
| MWMetal Works Corporation | Baton Rouge | LA | — | ◇ UNVERIFIED |
| MWMetal Works INC | Lexington | SC | — | ◇ UNVERIFIED |
| MWMetal Works Performance, Inc | Saint Charles | IL | — | ◇ UNVERIFIED |
| MMMetro Manufacturing INC | Saint Paul | MN | — | ◇ UNVERIFIED |
| MCMetroplex Conveyor & Services, LLC | Quinlan | TX | — | ◇ UNVERIFIED |
| MFMetroplex Fabrication and Erection, LLP | Azle | TX | — | ◇ UNVERIFIED |
| MSMetro Steel | Spring Valley | CA | — | ◇ UNVERIFIED |
| MBMetwood Building Solutions | Boones Mill | VA | — | ◇ UNVERIFIED |
| MCMexico City Iron Works | San Francisco | CA | — | ◇ UNVERIFIED |
| MCMeyers Construction INC | Madera | CA | — | ◇ UNVERIFIED |
 Meyer Utility Structures, LLC Plant No. 1663 | Hager City | WI | — | ◇ UNVERIFIED |
| MLMhs LTD Dba Wear Flex Slings | Winston Salem | NC | — | ◇ UNVERIFIED |
| MMMHS Management LLC | Pleasant Grove | UT | — | ◇ UNVERIFIED |
| MEMichael E Taylor | Oregon City | OR | — | ◇ UNVERIFIED |
| MZMichal Zieba | Brooklyn | NY | — | ◇ UNVERIFIED |
| MIMichelman-cancelliere Iron Works, INC. | Bath | PA | — | ◇ UNVERIFIED |
| MSMichelman Steel | Allentown | PA | — | ◇ UNVERIFIED |
| MWMichigan Wire Cloth LLC | Saint Johns | MI | — | ◇ UNVERIFIED |
| MPMicrotek Pattern Inc | Decatur | IL | — | ◇ UNVERIFIED |
| MSMid-america Steel Products, INC. | Corning | AR | — | ◇ UNVERIFIED |
| MSMid-atlantic Steel, LLC | New Castle | DE | — | ◇ UNVERIFIED |
| MCMid Continent Nail CORP | Radford | VA | — | ◇ UNVERIFIED |
| MCMid Continent Steel & Wire, INC. | Poplar Bluff | MO | — | ◇ UNVERIFIED |
| MFMidland Fabricators & Process Systems LLC | Metairie | LA | — | ◇ UNVERIFIED |
| MMMid-south Maintenance, INC. | Memphis | TN | — | ◇ UNVERIFIED |
| MMMid-state Machineand Fabricating CORP. | Lakeland | FL | — | ◇ UNVERIFIED |
| MMMidstate Manufacturing & Marketing, INC. | Oklahoma City | OK | — | ◇ UNVERIFIED |
| MVMid Valley Metal Works, Inc. | Salem | OR | — | ◇ UNVERIFIED |
| MVMid Valley Sheet Metal INC. | La Feria | TX | — | ◇ UNVERIFIED |
| MAMidwest Air Technologies, INC. | Port Wentworth | GA | — | ◇ UNVERIFIED |
| MMMidwest Manufacturing Corporation | Omaha | NE | — | ◇ UNVERIFIED |
| MRMidwest Racking Manufacturing, INC. | Madison | IL | — | ◇ UNVERIFIED |
| MSMidwest Steel and Rebar LLC | Seymour | MO | — | ◇ UNVERIFIED |
| MSMidwest Steel Fabricators CO INC | Wichita | KS | — | ◇ UNVERIFIED |
| MWMidwest Wire Products INC | Ferndale | MI | — | ◇ UNVERIFIED |
| MOMike Owen Fabrication | Bakersfield | CA | — | ◇ UNVERIFIED |
| MOMike Owens Fabrication, INC. | Lancaster | CA | — | ◇ UNVERIFIED |
| MMMikes Metal Works INC | Jamul | CA | — | ◇ UNVERIFIED |
| MJMikey Johns Outdoor, L.L.C. | Lake City | IA | — | ◇ UNVERIFIED |
| MFMillenium Facility Services INC | Tallapoosa | GA | — | ◇ UNVERIFIED |
| MEMillmark Enterprises, INC. | Elkhart | IN | — | ◇ UNVERIFIED |
| MMMill-Tech Manufacturing LLC | New London | WI | — | ◇ UNVERIFIED |
| MVMillvale Vault | Glenshaw | PA | — | ◇ UNVERIFIED |
