| NSNorthshore Steel INC | Two Harbors | MN | — | ◇ UNVERIFIED |
| NSNorth Star Fabricators, INC. | Pocatello | ID | — | ◇ UNVERIFIED |
| NTNorth Texas Steel | Fort Worth | TX | — | ◇ UNVERIFIED |
| NANorthwest Aluminum Trailers INC | Roseburg | OR | — | ◇ UNVERIFIED |
| NSNorthwest Steel Fab INC Deer Park | Deer Park | WA | — | ◇ UNVERIFIED |
| NSNorthwest Structural Services INC | Portland | OR | — | ◇ UNVERIFIED |
| NSNorthwest Structural Services INC | Portland | OR | — | ◇ UNVERIFIED |
| NSNorthwest Structural Services INC | Portland | OR | — | ◇ UNVERIFIED |
| NTNorthwest Thermal Systems INC | Estacada | OR | — | ◇ UNVERIFIED |
| NPNovel Precision Machine LLC | Lyndon | KY | — | ◇ UNVERIFIED |
| NSNowlin Steelcraft, INC. | Hampton | VA | — | ◇ UNVERIFIED |
| NTNozzle Tech USA, LLC | Springville | UT | — | ◇ UNVERIFIED |
| NNucor | Norfolk | NE | — | ◇ UNVERIFIED |
| NHNucor Harris Rebar Jackson LLC | Flowood | MS | — | ◇ UNVERIFIED |
| NHNucor Harris Rebar - Zellwood | Zellwood | FL | — | ◇ UNVERIFIED |
| NRNucor Rebar Fabrication Northeast LLC | Pawtucket | RI | — | ◇ UNVERIFIED |
| NRNucor Rebar Fabrication Southwest INC | Lathrop | CA | — | ◇ UNVERIFIED |
| NSNucor Skyline | Armorel | AR | — | ◇ UNVERIFIED |
| NTNucor Towers and Structures | New Ross | IN | — | ◇ UNVERIFIED |
| NTNucor Towers & Structures | Crawfordsville | IN | — | ◇ UNVERIFIED |
| NVNucor Vulcraft Group | San Antonio | TX | — | ◇ UNVERIFIED |
| NVNucor Vulcraft - St. Joe Division | Saint Joe | IN | — | ◇ UNVERIFIED |
| NSNuEra Steel LLC | Viborg | SD | — | ◇ UNVERIFIED |
| NCNueva Castilla Iron Works, INC. | San Francisco | CA | — | ◇ UNVERIFIED |
| NRNufab Rebar-slidell, LLC | Alexandria | LA | — | ◇ UNVERIFIED |
| NNNumber Nine, L.l.c. | Lk Havasu Cty | AZ | — | ◇ UNVERIFIED |
| NFNusteel Fabricators, INC. | Childersburg | AL | — | ◇ UNVERIFIED |
| NSNWA Steel Co LLC | Siloam Springs | AR | — | ◇ UNVERIFIED |
| OIOakdale Iron Works, INC. | Oakdale | PA | — | ◇ UNVERIFIED |
| OFOberlin Filter Company | Pewaukee | WI | — | ◇ UNVERIFIED |
| OCObie Construction, INC. | Eugene | OR | — | ◇ UNVERIFIED |
| OIOcci INC. Wwtp | Fulton | MO | — | ◇ UNVERIFIED |
 Occupational Development Center INC Dba Custom Pro | Bemidji | MN | — | ◇ UNVERIFIED |
| OSOcean Steel Corporation | Binghamton | NY | — | ◇ UNVERIFIED |
| OBOeg Building Materials INC. | Matawan | NJ | — | ◇ UNVERIFIED |
| OFOem Fabricators INC | Neillsville | WI | — | ◇ UNVERIFIED |
| OSOesterlings Sandblasting/butler | Butler | PA | — | ◇ UNVERIFIED |
| OAOgden Art Metal INC. | Murray | UT | — | ◇ UNVERIFIED |
| OPOgden Painting Facility | Ogden | UT | — | ◇ UNVERIFIED |
| OOgletree's | Saint Helena | CA | — | ◇ UNVERIFIED |
| OCOglivie Company INC the | Astoria | OR | — | ◇ UNVERIFIED |
| OHO H I Company | Stockton | CA | — | ◇ UNVERIFIED |
| OCOhi Company | Stockton | CA | — | ◇ UNVERIFIED |
| OSOhio Steel Industries (0145000318) | Pataskala | OH | — | ◇ UNVERIFIED |
| OSOhio Steel Industries, INC. | Summit Station | OH | — | ◇ UNVERIFIED |
| OVOhio Valley Fabrication and Energy INC. | Wheeling | WV | — | ◇ UNVERIFIED |
| OIOiw, INC. | Pelham | AL | — | ◇ UNVERIFIED |
| OLOiw LLC | Oakdale | PA | — | ◇ UNVERIFIED |
| OKO & K American CORP. | Chicago | IL | — | ◇ UNVERIFIED |
| OBOld Bridge Metal Fabrication Inc. | Riverside | CA | — | ◇ UNVERIFIED |
