| MCMueller Casting and Copper Tube Products | Fulton | MS | Primary Metal Manufacturing331420 | — | ◐ LIKELY ACTIVE |
| MIMultimetco INC | Anniston | AL | Primary Metal Manufacturing331314 | 20-99 | ◐ LIKELY ACTIVE |
| MCMuncie Casting CORP | Muncie | IN | Primary Metal Manufacturing331511 | — | ◐ LIKELY ACTIVE |
| NSNational Steel Rule | Linden | NJ | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| NPNaylor Pipe CO | Chicago | IL | Primary Metal Manufacturing331210 | 20-99 | ◐ LIKELY ACTIVE |
| NSNelsen Steel & Wire LP | Franklin Park | IL | Primary Metal Manufacturing331221 | — | ◐ LIKELY ACTIVE |
| NTNemak TEN | Dickson | TN | Primary Metal Manufacturing331524 | 100-499 | ◐ LIKELY ACTIVE |
| NANeturen America Corporation | Hamilton | OH | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| NSNippon Sharyo Manufacturing LLC | Rochelle | IL | Primary Metal Manufacturing331210 | — | ◐ LIKELY ACTIVE |
| NINlmk Indiana | Portage | IN | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NPNlmk Pennsylvania Lcc | Farrell | PA | Primary Metal Manufacturing331110 | 500+ | ◐ LIKELY ACTIVE |
| NCNorris Cylinder CO | Huntsville | AL | Primary Metal Manufacturing331492 | — | ◐ LIKELY ACTIVE |
| NSNorth Star Casteel Products | Seattle | WA | Primary Metal Manufacturing331513 | — | ◐ LIKELY ACTIVE |
| NSNorth Star Casteel Products | Seattle | WA | Primary Metal Manufacturing331513 | 20-99 | ◐ LIKELY ACTIVE |
| NSNorth Star Steel CO | Monroe | MI | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NANovelis Alr Recycling of Ohio LLC | Uhrichsville | OH | Primary Metal Manufacturing331314 | — | ◐ LIKELY ACTIVE |
| NANovelis Aluminum Mill | Oswego | NY | Primary Metal Manufacturing331313 | — | ◐ LIKELY ACTIVE |
| NCNovelis Corporation | Guthrie | KY | Primary Metal Manufacturing331315 | — | ◐ LIKELY ACTIVE |
| NHNre - Hagerstown, INC | Weston | WV | Primary Metal Manufacturing331511 | 1-19 | ◐ LIKELY ACTIVE |
| NINu-cast, INC. | Londonderry | NH | Primary Metal Manufacturing331523 | 20-99 | ◐ LIKELY ACTIVE |
| NCNucor CORP - Darlington Plant | Darlington | SC | Nonmetallic Mineral Product Manufacturing327320 | — | ◐ LIKELY ACTIVE |
| NCNucor Corporation | Norfolk | NE | Primary Metal Manufacturing331221 | — | ◐ LIKELY ACTIVE |
| NCNucor CORP Vulcraft Div | Brigham City | UT | Primary Metal Manufacturing331221 | — | ◐ LIKELY ACTIVE |
| NSNucor Steel - a Div of Nucor CORP | Plymouth | UT | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NSNucor Steel Auburn INC | Auburn | NY | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NSNucor Steel Birmingham INC | Birmingham | AL | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NSNucor Steel - Cofield Facility | Cofield | NC | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NSNucor Steel Florida, INC. | Frostproof | FL | Primary Metal Manufacturing331110 | 100-499 | ◐ LIKELY ACTIVE |
| NSNucor Steel Jackson INC | Flowood | MS | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NSNucor Steel Louisiana LLC | Convent | LA | Primary Metal Manufacturing331110 | 100-499 | ◐ LIKELY ACTIVE |
| NSNucor Steel Marion, INC. (0351010017) | Marion | OH | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
Nucor Steel Memphis INC | Memphis | TN | Primary Metal Manufacturing331221 | 500+ | ◐ LIKELY ACTIVE |
| NSNucor Steel Seattle INC | Seattle | WA | Primary Metal Manufacturing331110 | — | ◐ LIKELY ACTIVE |
| NSNucor Steel West Virginia LLC | Apple Grove | WV | Primary Metal Manufacturing331110 | 100-499 | ◐ LIKELY ACTIVE |
| NWNucor Wire Products Missouri | Maryville | MO | Primary Metal Manufacturing331221 | — | ◐ LIKELY ACTIVE |
| ODO & D Manufacturing | White Oak | TX | Primary Metal Manufacturing331529 | — | ◐ LIKELY ACTIVE |
| OMOerlikon Metco - Plymouth | Plymouth | MI | Primary Metal Manufacturing331492 | 20-99 | ◐ LIKELY ACTIVE |
| OOOffshore Operations Houston | Houston | TX | Primary Metal Manufacturing331110 | 100-499 | ◐ LIKELY ACTIVE |
| OPOhio Pickling & Processing | Toledo | OH | Primary Metal Manufacturing331221 | — | ◐ LIKELY ACTIVE |
| OHOwls Head Alloys INC | Bowling Green | KY | Primary Metal Manufacturing331314 | — | ◐ LIKELY ACTIVE |
| POPeerless of America INC | Effingham | IL | Primary Metal Manufacturing331316 | 20-99 | ◐ LIKELY ACTIVE |
| PAPenn Aluminum | Harlingen | TX | Primary Metal Manufacturing331316 | 20-99 | ◐ LIKELY ACTIVE |
| PSPenn State Special Metals LLC | Koppel | PA | Primary Metal Manufacturing331210 | — | ◐ LIKELY ACTIVE |
| PUPenn Union Corp/edinboro | Edinboro | PA | Primary Metal Manufacturing331529 | — | ◐ LIKELY ACTIVE |
| PFPentair Flow Technologies, LLC - Ashland Pump Plant (0303010175) | Ashland | OH | Primary Metal Manufacturing331511 | — | ◐ LIKELY ACTIVE |
| PCPerma Cast CO | Pueblo | CO | Primary Metal Manufacturing331524 | 1-19 | ◐ LIKELY ACTIVE |
| PJPhillips & Johnston INC Dba River Rock Fabrication | Grand Rapids | MI | Primary Metal Manufacturing331210 | — | ◐ LIKELY ACTIVE |
| PPPiad Precision Casting/hempfield Twp Plt | Greensburg | PA | Primary Metal Manufacturing331420 | — | ◐ LIKELY ACTIVE |
| PWPimalco (a Wholly-owned Subsidiary of Alcoa) | Chandler | AZ | Primary Metal Manufacturing331314 | — | ◐ LIKELY ACTIVE |
| PEPlymouth Engineered Shapes | Hopkinsville | KY | Primary Metal Manufacturing331210 | — | ◐ LIKELY ACTIVE |