| NMNick's Metal Fabricating & Sons, INC. | Chicago | IL | — | ◇ UNVERIFIED |
| NMNix Metals Fabrication Building Expansion | Poseyville | IN | — | ◇ UNVERIFIED |
| NCNooter Corporation | Saint Louis | MO | — | ◇ UNVERIFIED |
 North Alabama Fabricating Company, INC. | Glen Allen | AL | — | ◇ UNVERIFIED |
| NANorth American Construction Services, LLC | Birmingham | AL | — | ◇ UNVERIFIED |
| NCNorth Chicago Iron Works, INC. | North Chicago | IL | — | ◇ UNVERIFIED |
| NCNorth Coast Tool, INC. | Erie | PA | — | ◇ UNVERIFIED |
| NSNortheast Sheet Metal LLC | Hoboken | NJ | — | ◇ UNVERIFIED |
| NCNorthern California Framing & Carpentry, INC. | Ripon | CA | — | ◇ UNVERIFIED |
| NONorthern Oregon Fabrication LLC | North Plains | OR | — | ◇ UNVERIFIED |
| NSNorthern Screw Machine Company INC | Saint Paul | MN | — | ◇ UNVERIFIED |
 Northland Machine INC | Cohasset | MN | — | ◇ UNVERIFIED |
| NSNorth Second Street Smithfield LLC Dba Con-quip | Burlington | KY | — | ◇ UNVERIFIED |
| NSNorth Shore Steel Co., INC. | Lynn | MA | — | ◇ UNVERIFIED |
| NSNorth Star Fabricators, INC. | Pocatello | ID | — | ◇ UNVERIFIED |
| NMNorthstar Metalworks, INC | Brainerd | MN | — | ◇ UNVERIFIED |
| NSNorthstar Steel Fab. INC | Rhinelander | WI | — | ◇ UNVERIFIED |
| NTNorth Texas Steel | Fort Worth | TX | — | ◇ UNVERIFIED |
| NANorthwest Aluminum Trailers INC | Roseburg | OR | — | ◇ 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 |
| NINrlj, INC. | Browns Summit | NC | — | ◇ UNVERIFIED |
| NNucor | Norfolk | NE | — | ◇ UNVERIFIED |
| NHNucor Harris Rebar Jackson LLC | Flowood | MS | — | ◇ 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 |
| NNucraft | Roscommon | MI | — | ◇ 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 |
| OOO'brien Oilfield Services, LLC | Belfield | ND | — | ◇ UNVERIFIED |
 Occupational Development Center INC Dba Custom Pro | Bemidji | MN | — | ◇ UNVERIFIED |
| OSOcean Steel Corporation | Binghamton | NY | — | ◇ UNVERIFIED |
| OIOdom Industries, INC | Milford | OH | — | ◇ UNVERIFIED |
| OBOeg Building Materials INC. | Matawan | NJ | — | ◇ UNVERIFIED |
| OIOfab, INC. | Ocala | FL | — | ◇ UNVERIFIED |
| OAOgden Art Metal INC. | Murray | UT | — | ◇ UNVERIFIED |
| OOgletree's | Saint Helena | CA | — | ◇ 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 |
| OIOldcastle Infrastructure - Azusa 10th | Azusa | CA | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure - Azusa Dalou | Azusa | CA | — | ◇ UNVERIFIED |
| OCOlson & Company Steel | Fresno | CA | — | ◇ UNVERIFIED |
| OIOlson Iron & Stone Creations LLC | Elk River | MN | — | ◇ UNVERIFIED |
| OSOlson Steel | San Leandro | CA | — | ◇ UNVERIFIED |
| OTOlympus Technologies Incorporated | Eugene | OR | — | ◇ UNVERIFIED |
| OHOmco - Huntsville | Madison | AL | — | ◇ UNVERIFIED |
| OROmco Roll Forming Plus - Wickliffe | Wickliffe | OH | — | ◇ UNVERIFIED |
| OSOmega Steel Products, INC | Jemison | AL | — | ◇ UNVERIFIED |
| OMO & M Fabricators, LLC | Pensacola | FL | — | ◇ UNVERIFIED |
| OIOmni Industrial Services | Buffalo | WV | — | ◇ UNVERIFIED |
| OTOn Time Fab INC | Saint Joseph | KY | — | ◇ UNVERIFIED |
| OFOpc Fabrication and Equipment, INC. (fn) | Phoenix | AZ | — | ◇ UNVERIFIED |
| OSOrange State Steel | Bartow | FL | — | ◇ UNVERIFIED |
| OSOrange State Steel Construction, INC. | Riverview | FL | — | ◇ UNVERIFIED |
| OCOrco Construction Supply | Bloomington | CA | — | ◇ UNVERIFIED |
| ODOreco Duct System INC | Baldwin Park | CA | — | ◇ UNVERIFIED |
| OPOregon Pacific Structural Fabrication, LLC | Mulino | OR | — | ◇ UNVERIFIED |
| OTOrganic Transit INC. | Durham | NC | — | ◇ UNVERIFIED |
| OEOri Enterprises LLC | Price | UT | — | ◇ UNVERIFIED |
| OIOrlando Iron Works | Paterson | NJ | — | ◇ UNVERIFIED |
| OWOsborne Welding, INC. | Hampton | VA | — | ◇ UNVERIFIED |
| OAOshkosh Aerotech - Jetway Systems | Ogden | UT | — | ◇ UNVERIFIED |
| OIOssi's Iron Works | Las Vegas | NV | — | ◇ UNVERIFIED |
| OIOutlaw Industries, LLC | Clinton | LA | — | ◇ UNVERIFIED |
| OSOwens & Sons, INC. | Metairie | LA | — | ◇ UNVERIFIED |
| OBOzark Barge & Dock Service Inc.* | Gravois Mills | MO | — | ◇ UNVERIFIED |
| PBPacific Bend | Hemet | CA | — | ◇ UNVERIFIED |
| PEPacific Embedment Products | Adelanto | CA | — | ◇ UNVERIFIED |
| PFPacific Fabrication INC | Rancho Cucamonga | CA | — | ◇ UNVERIFIED |
| PRPacific Rebar INC | Ontario | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Bloomington | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Bloomington | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Stockton | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Livermore | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Benicia | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Napa | CA | — | ◇ UNVERIFIED |
| PWPacific Welding Services | Asan | GU | — | ◇ UNVERIFIED |
| PTPalmer Tool Company | Camden | TN | — | ◇ UNVERIFIED |
| PMPanhandle Machine LLC | Priest River | ID | — | ◇ UNVERIFIED |
| PMPanhandle Metal Fabrication, INC. | Pensacola | FL | — | ◇ UNVERIFIED |
