| MMMonarch Machine & Tool Co., INC. | Pasco | WA | — | ◐ LIKELY ACTIVE |
| MMMonarch Materials Group, Inc. | Adel | IA | 20–99 | ◐ LIKELY ACTIVE |
| MCMoody Construction Services, Inc. | Duette | FL | 20–99 | ◐ LIKELY ACTIVE |
| MMMoore Metal Works, LLC | Evansville | IN | 20–99 | ◐ LIKELY ACTIVE |
| MSMorgan Steel Texas, LLC | Greenville | TX | 20–99 | ◐ LIKELY ACTIVE |
| MWMorningstar Welding, LLC | Poolesville | MD | — | ◐ LIKELY ACTIVE |
| MIMultiMetal Inc, dba Moore & Morford II | Greensburg | PA | 20–99 | ◐ LIKELY ACTIVE |
| Mmunster1501 | Hammond | IN | 20–99 | ◐ LIKELY ACTIVE |
| NNARSTCO-Midlothian | Midlothian | TX | 20–99 | ◐ LIKELY ACTIVE |
| NGNational Galvanizing | Monroe | MI | 100–499 | ◐ LIKELY ACTIVE |
| NCNativewest CORP | West Linn | OR | — | ◐ LIKELY ACTIVE |
| NNc01-yis | Jacksonville | NC | 1–19 | ◐ LIKELY ACTIVE |
| NNc03-yis | Jacksonville | NC | 1–19 | ◐ LIKELY ACTIVE |
| NCNc Carports and Garages LLC | Elkin | NC | — | ◐ LIKELY ACTIVE |
| NMNew Millennium Building Systems, LLC. - Columbia | Columbia | SC | 20–99 | ◐ LIKELY ACTIVE |
| NMNew Millennium Building Systems, LLC. - Fallon | Fallon | NV | 100–499 | ◐ LIKELY ACTIVE |
| NMNew Millennium Building Systems, LLC. - Northwest Arkansas Engineering | Rogers | AR | 20–99 | ◐ LIKELY ACTIVE |
| NNiles | Niles | OH | 20–99 | ◐ LIKELY ACTIVE |
| NBNiles Building Products Company - Florida | Jacksonville | FL | 20–99 | ◐ LIKELY ACTIVE |
| NBNiles Building Products Company - Ohio | Niles | OH | 1–19 | ◐ LIKELY ACTIVE |
| NBNiles Building Products Company - Texas | Grand Prairie | TX | 1–19 | ◐ LIKELY ACTIVE |
| NSNimsgern Steel Corp. | Minocqua | WI | 20–99 | ◐ LIKELY ACTIVE |
| NSNippon Steel Pipe America Inc | Seymour | IN | 100–499 | ◐ LIKELY ACTIVE |
| NINix Industrial - Fairfield, OH | Farifield | OH | 1–19 | ◐ LIKELY ACTIVE |
| NINix Industrial - Frontage Road | Poseyville | IN | 20–99 | ◐ LIKELY ACTIVE |
| NINix Industrial - Main Street | Poseyville | IN | 20–99 | ◐ LIKELY ACTIVE |
| NINix Industrial - Rockport, IN | Rockport | IN | 20–99 | ◐ LIKELY ACTIVE |
| NINN, Inc. Palmer | Palmer | MA | 1–19 | ◐ LIKELY ACTIVE |
| NGNorfork General Industries, Inc | Norfork | AR | 20–99 | ◐ LIKELY ACTIVE |
| NSNorlen - Schofield | Schofield | WI | 100–499 | ◐ LIKELY ACTIVE |
| NANorth American Manufacturing Corp. | Maspeth | NY | 1–19 | ◐ LIKELY ACTIVE |
| NHNorthern Horizons Solway, Inc | Solway | MN | 100–499 | ◐ LIKELY ACTIVE |
| NSNorthern Steel Services, L.L.C. | Montrose | MI | 20–99 | ◐ LIKELY ACTIVE |
| NTNorth Texas Pressure Vessels, Inc. | Mineral Wells | TX | 20–99 | ◐ LIKELY ACTIVE |
| NWNuark Warehouse & Logistics | Blytheville | AR | 20–99 | ◐ LIKELY ACTIVE |
| NCNucor Corporation | Jewett | TX | — | ◐ LIKELY ACTIVE |
| NHNucor Harris Rebar Mid-Atlantic LLC (Baltimore Facility) | Baltimore | MD | 20–99 | ◐ LIKELY ACTIVE |
| NHNucor Harris Rebar Northeast LLC (Bethlehem Facility) | Bethlehem | PA | 20–99 | ◐ LIKELY ACTIVE |
| NHNucor Harris Rebar Northeast LLC (Canaan Facility) | Canaan | NH | 20–99 | ◐ LIKELY ACTIVE |
| NHNucor Harris Rebar Northeast LLC (Pawtucket Facility) | Pawtucket | RI | 20–99 | ◐ LIKELY ACTIVE |
| NHNucor Harris Rebar Northeast LLC (South Deerfield Facility) | South Deerfield | MA | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC Bourbonnais, Illinois | Bourbonnais | IL | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC Lansing, Michigan | Lansing | MI | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC Marion, Ohio | Marion | OH | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC Mooresville, Indiana | Mooresville | IN | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC - Newton Iowa | Newton | IA | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC - Roberts Wisonsin | Roberts | WI | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC Rockford, Illinois | Rockford | IL | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC - Sedalia Missouri | Sedalia | MO | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Midwest LLC - St. Louis Missouri | Saint Louis | MO | 1–19 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Services Center Corp | Fort Wayne | IN | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Southcentral LLC - Dallas Texas | Dallas | TX | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Southcentral LLC - Houston Texas | Dayton | TX | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Southcentral LLC - Jackson Mississippi | Flowood | MS | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Southcentral LLC - Jewett Texas | Jewett | TX | 20–99 | ◐ LIKELY ACTIVE |
| NRNucor Rebar Fabrication Southcentral LLC - Slidell Louisiana | Slidell | LA | 20–99 | ◐ LIKELY ACTIVE |
| NSNucor Skyline | Huger | SC | 20–99 | ◐ LIKELY ACTIVE |
| NSNucor Skyline | Belpre | OH | 20–99 | ◐ LIKELY ACTIVE |
| NSNucor Steel Hertford County | Cofield | NC | 100–499 | ◐ LIKELY ACTIVE |
| NSNucor Steel Jewett TX | Jewett | TX | 100–499 | ◐ LIKELY ACTIVE |
| NSNucor Steel Seattle INC. | Seattle (SEA) | WA | 100–499 | ◐ LIKELY ACTIVE |
| NTNucor Towers and Structures Indiana | New Ross | IN | 100–499 | ◐ LIKELY ACTIVE |
| NTNucor Towers & Structures Inc | West Hazleton | PA | 100–499 | ◐ LIKELY ACTIVE |
| NDNucor (Vulcraft Division) | Saint Joe | IN | 100–499 | ◐ LIKELY ACTIVE |
| NENuena Enterprises, LLC | Houston | TX | — | ◐ LIKELY ACTIVE |
| NINuno Iron & Mfg. Inc. | King City | CA | 20–99 | ◐ LIKELY ACTIVE |
| NLNuverde, LLC | Austin | TX | — | ◐ LIKELY ACTIVE |
| NFNuway Fab | Troy | IL | 1–19 | ◐ LIKELY ACTIVE |
| OMO'Brien Metal Works | Clover | SC | 1–19 | ◐ LIKELY ACTIVE |
| OIOcci, INC. | Fulton | MO | — | ◐ LIKELY ACTIVE |
| OBOhio Bridge Manufacturing | Cambridge | OH | 20–99 | ◐ LIKELY ACTIVE |
| OMOhio Moulding | Wickliffe | OH | 20–99 | ◐ LIKELY ACTIVE |
| OSOhio Steel Industries Inc - Structural Division | Pataskala | OH | 20–99 | ◐ LIKELY ACTIVE |
| OSOmega Steel, Inc. | Bloomingdale | GA | 20–99 | ◐ LIKELY ACTIVE |
| OIONI Industries | Ambridge | PA | 100–499 | ◐ LIKELY ACTIVE |
| OOPTA-Affival | New Kensington | PA | 20–99 | ◐ LIKELY ACTIVE |
| OHOPTA-Burns Harbor | Burns Harbor | IN | 1–19 | ◐ LIKELY ACTIVE |
| OOPTA-Cleveland | Cleveland | OH | 1–19 | ◐ LIKELY ACTIVE |
| OOPTA-Dearborn | Dearborn | MI | 1–19 | ◐ LIKELY ACTIVE |
| OTOPTA-Edgar Thomson | Braddock | PA | 1–19 | ◐ LIKELY ACTIVE |
| OOPTA-Middletown | Middletown | OH | 1–19 | ◐ LIKELY ACTIVE |
| OWOptimized Welding Services LLC | El Paso | TX | — | ◐ LIKELY ACTIVE |
| OTOregon Trail Fabrication LLC | Salem | OR | — | ◐ LIKELY ACTIVE |
| OWOscar's Welding Svcs LLC | Odessa | TX | — | ◐ LIKELY ACTIVE |
| OOttawa | Ottawa | KS | 20–99 | ◐ LIKELY ACTIVE |
| OSOutokumpu Stainless USA LLC | Calvert | AL | 500+ | ◐ LIKELY ACTIVE |
| OOwensboro | Owensboro | KY | 20–99 | ◐ LIKELY ACTIVE |
| OSOzark Steel, LLC | Farmington | MO | 20–99 | ◐ LIKELY ACTIVE |
| PAPa35 Ametek Smp Eighty Four | Eighty Four | PA | 20–99 | ◐ LIKELY ACTIVE |
| PSPacific Stair Corporation - CA | Los Angeles | CA | 1–19 | ◐ LIKELY ACTIVE |
| POPageland Operations | Pageland | SC | 20–99 | ◐ LIKELY ACTIVE |
| PWParker Welding & Fabrication LLC | Greenleaf | KS | — | ◐ LIKELY ACTIVE |
| PIPatrick Industries, Inc. d/b/a/ Engineered Metals & Composites Inc | West Columbia | SC | 100–499 | ◐ LIKELY ACTIVE |
| PTPatriot Trinity | Trinity | TX | 100–499 | ◐ LIKELY ACTIVE |
| PPhoenix | Phoenix | AZ | 1–19 | ◐ LIKELY ACTIVE |
| PGPhoenix Global, LLC-Burns Harbor | Burns Harbor | IN | 100–499 | ◐ LIKELY ACTIVE |
| PGPhoenix Global, LLC-Calvert-OTK | Calvert | AL | 20–99 | ◐ LIKELY ACTIVE |
| PGPhoenix Global, LLC-Cool Springs | Mingo Junction | OH | 1–19 | ◐ LIKELY ACTIVE |
| PGPhoenix Global, LLC-Fairfield | Fairfield | AL | 20–99 | ◐ LIKELY ACTIVE |
| PGPhoenix Global, LLC-Fort Smith | Fort Smith | AR | 20–99 | ◐ LIKELY ACTIVE |