| 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 |
| 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 |
| MUMinova USA INC | South Point | OH | — | ◇ UNVERIFIED |
| MMMisener Marine Construction, INC. | Tampa | FL | — | ◇ UNVERIFIED |
| MDMissouri Dry Dock & Repair CO | Cape Girardeau | MO | — | ◇ UNVERIFIED |
| MVMissouri Valley Steel Company | Sioux City | IA | — | ◇ UNVERIFIED |
| MCMjk Custom Fab and Coatings LLC | Ogden | UT | — | ◇ UNVERIFIED |
| MSMka Spray Service | Lawrence | MA | — | ◇ UNVERIFIED |
| MMMk Metal Products Enterprises INC | Mansfield | OH | — | ◇ UNVERIFIED |
| MWModern Welding CO of Kentucky INC | Hardin County | KY | — | ◇ UNVERIFIED |
| MMModine Mfg CO - Former Site of | Washington | IA | — | ◇ UNVERIFIED |
| MWMonarch Ware INC | Algoma | WI | — | ◇ UNVERIFIED |
| MRMowata Rice Drier INC - Southern Rice Drier & Storage CO | Rayne | LA | — | ◇ UNVERIFIED |
| MMMulberry Manufacturing CO | Mulberry | FL | — | ◇ UNVERIFIED |
| MPMulti-craft Plastics | Portland | OR | — | ◇ UNVERIFIED |
| MSMunster Steel Company | Munster | IN | — | ◇ UNVERIFIED |
| NCNai Cranes LLC | Woburn | MA | — | ◇ UNVERIFIED |
| NVNashoba Valley Structural | Lunenburg | MA | — | ◇ UNVERIFIED |
| NBNci Bldg Sys Inc/ambridge | Ambridge | PA | — | ◇ UNVERIFIED |
| NPNekoosa Packaging, Memphis Boxplant | Memphis | TN | — | ◇ UNVERIFIED |
| NUNeoplan USA CORP | Lamar | CO | — | ◇ UNVERIFIED |
| NMNew Millenium Building Systems | Continental | OH | — | ◇ UNVERIFIED |
| NMNew Millennium Building System S INC | Florence | SC | — | ◇ UNVERIFIED |
| NNNewport News Shipbuilding Oakland Industrial Oip | Newport News | VA | — | ◇ UNVERIFIED |
| NLNext Level Metal | Baldwin | IL | — | ◇ UNVERIFIED |
| NWNiermann Weeks Company, INC | Millersville | MD | — | ◇ UNVERIFIED |
| NMNolin Milling INC | Dickens | IA | — | ◇ UNVERIFIED |
| NMNorthern Metal Fab INC | Baldwin | WI | — | ◇ UNVERIFIED |
| NGNorthrop Grumman Ship Systems INC | Waggaman | LA | — | ◇ UNVERIFIED |
| NSNorthshore Steel INC | Two Harbors | MN | — | ◇ UNVERIFIED |
| NSNorth State Steel Incorporated | Greenville | NC | — | ◇ UNVERIFIED |
| NSNorthwest Steel Fab INC Deer Park | Deer Park | WA | — | ◇ UNVERIFIED |
| OFOberlin Filter Company | Pewaukee | WI | — | ◇ UNVERIFIED |
| OCObie Construction, INC. | Eugene | OR | — | ◇ UNVERIFIED |
| OIOcci INC. Wwtp | Fulton | MO | — | ◇ UNVERIFIED |
| OSOcean Steel CORP | Conklin | NY | — | ◇ UNVERIFIED |
| OFOem Fabricators INC | Neillsville | WI | — | ◇ UNVERIFIED |
| OCOglivie Company INC the | Astoria | OR | — | ◇ UNVERIFIED |
| OSOhio Steel Industries | Pataskala | OH | — | ◇ UNVERIFIED |
| OEOmega Engineering INC | Bridgeport | NJ | — | ◇ UNVERIFIED |
| ONOmega Natchiq New Iberia Facility | New Iberia | LA | — | ◇ UNVERIFIED |
| OSOne Source Systems LLC | Vicksburg | MS | — | ◇ UNVERIFIED |
| OSOrange State Steel Construction, INC | Pinellas Park | FL | — | ◇ UNVERIFIED |
| OOOrchid Orthopedics | Arcadia | CA | — | ◇ UNVERIFIED |
| OIOregon Iron Works Hidden Way | Vancouver | WA | — | ◇ UNVERIFIED |
| OIOregon Iron Works INC 3001 | Vancouver | WA | — | ◇ UNVERIFIED |
| OMOrion Marine Construction, INC | Tampa | FL | — | ◇ UNVERIFIED |
| OMOrnamental Metalworks INC | Decatur | IL | — | ◇ UNVERIFIED |
| OSOutland Steel, INC. | Caldwell | ID | — | ◇ UNVERIFIED |
| OSOzark Steel Fabricators INC | Farmington | MO | — | ◇ UNVERIFIED |
| PSPabrico Steel Fabricators | Paterson | NJ | — | ◇ UNVERIFIED |
| PIPacal Industries LLC | La Crosse | WI | — | ◇ UNVERIFIED |
| PWPampa Wind Tower Manufacturing Facility | Pampa | TX | — | ◇ UNVERIFIED |
| PPParton & Preble INC | Warren | MI | — | ◇ UNVERIFIED |
| PPPdm Precast | Carlisle | IA | — | ◇ UNVERIFIED |
| PMPelican Metal Products LLC | Harrison Township | MI | — | ◇ UNVERIFIED |
| PPPenz Products, INC. | Mishawaka | IN | — | ◇ UNVERIFIED |
| PEPerformance Energy Services LLC - Amelia Yard | Morgan City | LA | — | ◇ UNVERIFIED |
| PMPhilipp Mfg CO INC | Easthampton | MA | — | ◇ UNVERIFIED |
| PHP & H Mining Equipment | Milwaukee | WI | — | ◇ UNVERIFIED |
| PMPhoenix Manufacturing CO | Memphis | TN | — | ◇ UNVERIFIED |
| PMPhoenix Metalcraft | Phoenix | AZ | — | ◇ UNVERIFIED |
| PVPinson Valley Fabricators INC | Birmingham, Al | AL | — | ◇ UNVERIFIED |
| PAPioneer Aerospace CORP | Milton | FL | — | ◇ UNVERIFIED |
| PCPioneer Consolidated | North Oxford | MA | — | ◇ UNVERIFIED |
| PSPneu-mech Systems Manufacturing INC | Statesville | NC | — | ◇ UNVERIFIED |
| PSPortersville Sales & Testing/portersville | Portersville | PA | — | ◇ UNVERIFIED |
| PWPorter Welding INC | Zanesville | OH | — | ◇ UNVERIFIED |
| PAPostle Aluminum (p0448) | Cassopolis | MI | — | ◇ UNVERIFIED |
| PBPrecision Build Solutions, LLC | Tampa | FL | — | ◇ UNVERIFIED |
