| MIMost INC | Troy | MO | Primary Metal Manufacturing331314 | 20-99 | ◐ LIKELY ACTIVE |
| MCMueller CO | Albertville | AL | Primary Metal Manufacturing331511 | 500+ | ◐ LIKELY ACTIVE |
| MFMueller Fittings CO INC | Covington | TN | Primary Metal Manufacturing331420 | 20-99 | ◐ LIKELY ACTIVE |
| MCMulti-cast CORP | Wauseon | OH | Primary Metal Manufacturing331521 | 20-99 | ◐ LIKELY ACTIVE |
| NUNemak USA INC | Glasgow | KY | Primary Metal Manufacturing331521 | 100-499 | ◐ LIKELY ACTIVE |
| NENew England Union Co., INC. | West Warwick | RI | Primary Metal Manufacturing331528 | 20-99 | ◐ LIKELY ACTIVE |
| NMNielsen Moulding, LLC | Gainesboro | TN | Primary Metal Manufacturing331316 | 20-99 | ◐ LIKELY ACTIVE |
| NANorth American Hydraulic Excavation Facility | Victoria | TX | Primary Metal Manufacturing331210 | 100-499 | ◐ LIKELY ACTIVE |
| NVNorth Vernon Industry CORP | North Vernon | IN | Primary Metal Manufacturing331511 | 100-499 | ◐ LIKELY ACTIVE |
| NPNorthwest Pipe CO | Adelanto | CA | Primary Metal Manufacturing331210 | 100-499 | ◐ LIKELY ACTIVE |
| NPNtk Precision Axle CORP | Frankfort | IN | Primary Metal Manufacturing331221 | 100-499 | ◐ LIKELY ACTIVE |
| NFNucor Fastener Shelbyville | Shelbyville | IN | Primary Metal Manufacturing331222 | 20-99 | ◐ LIKELY ACTIVE |
| NSNucor Steel | Norfolk | NE | Primary Metal Manufacturing331110 | 500+ | ◐ LIKELY ACTIVE |
| NSNucor Steel Connecticut, INC. | Wallingford | CT | Primary Metal Manufacturing331110 | 20-99 | ◐ LIKELY ACTIVE |
| NSNucor Steel Kankakee INC | Bourbonnais | IL | Primary Metal Manufacturing331110 | 100-499 | ◐ LIKELY ACTIVE |
| NSNucor Steel Kingman LLC | Kingman | AZ | Primary Metal Manufacturing331110 | 100-499 | ◐ LIKELY ACTIVE |
| NTNucor Tubular Products INC | Decatur | AL | Primary Metal Manufacturing331210 | 100-499 | ◐ LIKELY ACTIVE |
Nyrstar Clarksville INC. | Clarksville | TN | Chemical Manufacturing325188 | — | ◐ LIKELY ACTIVE |
| OFO'hare Foundry Corporation | Maplewood | MO | Primary Metal Manufacturing331523 | 20-99 | ◐ LIKELY ACTIVE |
| OAOhio Aluminum Industries INC. | Cleveland | OH | Primary Metal Manufacturing331524 | 100-499 | ◐ LIKELY ACTIVE |
| OSOmaha Steel Castings | Wahoo | NE | Primary Metal Manufacturing331513 | 20-99 | ◐ LIKELY ACTIVE |
| OOOrchid Orthopedic Solutions Oregon, INC | Oregon City | OR | Primary Metal Manufacturing331512 | — | ◐ LIKELY ACTIVE |
| PSPcc Schlosser | Redmond | OR | Primary Metal Manufacturing331512 | 100-499 | ◐ LIKELY ACTIVE |
| PSPcc Structurals | Carson City | NV | Primary Metal Manufacturing331512 | 100-499 | ◐ LIKELY ACTIVE |
| PAPermalok - a Northwest Pipe CO | St Louis | MO | Primary Metal Manufacturing331210 | 1-19 | ◐ LIKELY ACTIVE |
| PTPhoenix Tube CO | Bethlehem | PA | Primary Metal Manufacturing331210 | 100-499 | ◐ LIKELY ACTIVE |
Powder Alloy CORP | Loveland | OH | Primary Metal Manufacturing331410 | — | ◐ LIKELY ACTIVE |
| PAPremier Aluminum INC | Racine | WI | Primary Metal Manufacturing331521 | 20-99 | ◐ LIKELY ACTIVE |
| PFProgressive Foundry INC | Perry | IA | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| PCPrysmian Cables & Systems USA | Paragould | AR | Primary Metal Manufacturing331420 | 100-499 | ◐ LIKELY ACTIVE |
| PPPrysmian Power Cables and Systems Usa, LLC | Abbeville | SC | Primary Metal Manufacturing331420 | 20-99 | ◐ LIKELY ACTIVE |
| PGPsg Grand Rapids (previously Blackmer, a Dover Co) | Grand Rapids | MI | Primary Metal Manufacturing331511 | 100-499 | ◐ LIKELY ACTIVE |
| PTPtc Tubular Products LLC | Fairbury | IL | Primary Metal Manufacturing331210 | 20-99 | ◐ LIKELY ACTIVE |
| RAReal Alloy Recycling LLC | Sapulpa | OK | Primary Metal Manufacturing331314 | 20-99 | ◐ LIKELY ACTIVE |
| RAReal Alloy Recycling LLC | Wabash | IN | Primary Metal Manufacturing331314 | 20-99 | ◐ LIKELY ACTIVE |
| RAReal Alloy Specification LLC | Coldwater | MI | Primary Metal Manufacturing331313 | 20-99 | ◐ LIKELY ACTIVE |
| RMRea Magnet Wire Company INC | Lafayette | IN | Primary Metal Manufacturing331318 | 100-499 | ◐ LIKELY ACTIVE |
| RCRepublic Conduit | Louisville | KY | Primary Metal Manufacturing331210 | 100-499 | ◐ LIKELY ACTIVE |
| RIRexnord Industries LLC Gear Group | Milwaukee | WI | Primary Metal Manufacturing331513 | — | ◐ LIKELY ACTIVE |
| RERimer Enterprises INC | Waterville | OH | Primary Metal Manufacturing331512 | 20-99 | ◐ LIKELY ACTIVE |
| RTRmi Titanium CO (0278060189) | Niles | OH | Primary Metal Manufacturing331491 | — | ◐ LIKELY ACTIVE |
| RCRollex CORP | Elk Grove Village | IL | Primary Metal Manufacturing331524 | 100-499 | ◐ LIKELY ACTIVE |
| RARti Advanced Forming INC | Washington | MO | Primary Metal Manufacturing331221 | 20-99 | ◐ LIKELY ACTIVE |
| RHRyder Heil Bronze INC | Bucyrus | OH | Primary Metal Manufacturing331523 | 20-99 | ◐ LIKELY ACTIVE |
| RDRyobi Die Casting (usa), INC. | Shelbyville | IN | Primary Metal Manufacturing331521 | 500+ | ◐ LIKELY ACTIVE |
| SISancast INC | Coshocton | OH | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| SNScepter New York INC | Seneca Falls | NY | Primary Metal Manufacturing331314 | 20-99 | ◐ LIKELY ACTIVE |
| SFSeneca Foundry INC | Webster City | IA | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| SLSignicast LLC - Brown Deer | Milwaukee | WI | Primary Metal Manufacturing331510 | 100-499 | ◐ LIKELY ACTIVE |
| SASkana Aluminum Company | Manitowoc | WI | Primary Metal Manufacturing331314 | 100-499 | ◐ LIKELY ACTIVE |