| NCNorthwind Concrete Products CO | South Beloit | IL | — | ◇ UNVERIFIED |
| NCNorthwind Concrete Products CO | Posen | IL | — | ◇ UNVERIFIED |
| NPNorton Packaging, INC | Oakland | CA | — | ◇ UNVERIFIED |
| NNNortrax New Building | Miami | FL | — | ◇ UNVERIFIED |
 Norwalk Concrete Industries, INC. | Norwalk | OH | — | ◇ UNVERIFIED |
| NVNorwalk Vault CO. of Missouri INC. | Saint Louis | MO | — | ◇ UNVERIFIED |
| NSNorwood Sales INC. | Horace | ND | — | ◇ UNVERIFIED |
| NCNova Crete, INC. | Fort Lee | NJ | — | ◇ UNVERIFIED |
| NANov Ameron | Anniston | AL | — | ◇ UNVERIFIED |
| NPNovel Precision Machine LLC | Lyndon | KY | — | ◇ UNVERIFIED |
| NSNowlin Steelcraft, INC. | Hampton | VA | — | ◇ UNVERIFIED |
| NINucast Industries INC | Corona | CA | — | ◇ 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 |
| NLNurazzo, LLC | Dalton | GA | — | ◇ UNVERIFIED |
| NFNusteel Fabricators, INC. | Childersburg | AL | — | ◇ UNVERIFIED |
| NINutra-Boss Inc | Blue Earth | MN | — | ◇ UNVERIFIED |
| NSNWA Steel Co LLC | Siloam Springs | AR | — | ◇ UNVERIFIED |
| NCNW Concrete Vent Wells LLC | Gervais | OR | — | ◇ UNVERIFIED |
| NMNw Mixer Feeders | Caldwell | ID | — | ◇ UNVERIFIED |
| OIOakdale Iron Works, INC. | Oakdale | PA | — | ◇ UNVERIFIED |
| OCOaks Concrete Products INC | Wixom | MI | — | ◇ UNVERIFIED |
| OSOak Street Tank & Steel INC | Ashland | OR | — | ◇ UNVERIFIED |
| OLOberfield's LLC | Delaware | OH | — | ◇ UNVERIFIED |
| OFOberlin Filter Company | Pewaukee | WI | — | ◇ UNVERIFIED |
| OCObie Construction, INC. | Eugene | OR | — | ◇ UNVERIFIED |
| OBO'bryan Barrel CO INC | Evansville | IN | — | ◇ UNVERIFIED |
| OBObryan Barrel Company Incorporated | Evansville | IN | — | ◇ UNVERIFIED |
| OIOcci INC. Wwtp | Fulton | MO | — | ◇ UNVERIFIED |
 Occupational Development Center INC Dba Custom Pro | Bemidji | MN | — | ◇ UNVERIFIED |
| OGOcean Granite and Marble LLC | Little Egg Harbor Twp | NJ | — | ◇ UNVERIFIED |
| OSOcean Steel Corporation | Binghamton | NY | — | ◇ UNVERIFIED |
| OBOeg Building Materials INC. | Matawan | NJ | — | ◇ UNVERIFIED |
| OFOem Fabricators INC | Neillsville | WI | — | ◇ UNVERIFIED |
| OIOesco INC | Conway | MA | — | ◇ UNVERIFIED |
| OSOesterlings Sandblasting/butler | Butler | PA | — | ◇ UNVERIFIED |
| OAOgden Art Metal INC. | Murray | UT | — | ◇ UNVERIFIED |
| OCOgden Concrete Batch Plant G19 | 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 |
| OOldcastle | Keizer | OR | — | ◇ UNVERIFIED |
| OOldcastle | Lebanon | PA | — | ◇ UNVERIFIED |
| OOldcastle | Eugene | OR | — | ◇ UNVERIFIED |
| OAOldcastle Apg South INC | Rockwood | TN | — | ◇ UNVERIFIED |
| OCOldcastle Coastal | Tampa | FL | — | ◇ UNVERIFIED |
| OCOldcastle Coastal, INC. | Jacksonville | FL | — | ◇ UNVERIFIED |
| OEOldcastle Enclosure Solutions | Tracy | CA | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Romeoville | IL | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Nampa | ID | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Midway | FL | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Acworth | GA | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure - Azusa 10th | Azusa | CA | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure - Azusa Dalou | Azusa | CA | — | ◇ UNVERIFIED |
 Oldcastle Infrastructure, INC - Fontana | Fontana | CA | — | ◇ UNVERIFIED |
| Oldcastle Infrastructure, INC. - Phoenix Oes | Phoenix | AZ | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure - Platteville | Loveland Area | CO | — | ◇ UNVERIFIED |
| ONOldcastle Nampa Madison | Nampa | ID | — | ◇ UNVERIFIED |
| OPOldcastle Precast | Perris | CA | — | ◇ UNVERIFIED |
| OPOldcastle Precast | Fontana | CA | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Elk River | MN | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Stone Mountain | GA | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Bartow | FL | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Clackamas | OR | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Tualatin | OR | — | ◇ UNVERIFIED |
| OPOldcastle Precast, INC. | Ontario | CA | — | ◇ UNVERIFIED |
| OSOldcastle Savannah | Guyton | GA | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group- Port Concrete Plant | Gunnison | CO | — | ◇ UNVERIFIED |
| OWOldcastle Westile, INC. | Littleton | CO | — | ◇ UNVERIFIED |
| OCOlson & Company Steel | Fresno | CA | — | ◇ UNVERIFIED |
| OSOlson Steel | San Leandro | CA | — | ◇ UNVERIFIED |
| OMOlympic Marble | Buena Park | CA | — | ◇ UNVERIFIED |
| OTOlympus Technologies Incorporated | Eugene | OR | — | ◇ UNVERIFIED |
| OWOmaha Wilbert Vault, INC. | Omaha | NE | — | ◇ UNVERIFIED |
| ONOmega Natchiq New Iberia Facility | New Iberia | LA | — | ◇ UNVERIFIED |
| OPOmega Products International, INC. | Commerce City | CO | — | ◇ UNVERIFIED |
| OSOmega Steel Products, INC | Jemison | AL | — | ◇ UNVERIFIED |
| OMO & M Fabricators, LLC | Pensacola | FL | — | ◇ UNVERIFIED |
| OIOmni Industrial Services | Buffalo | WV | — | ◇ UNVERIFIED |
| OPOmni Products, INC. | Lincolnton | NC | — | ◇ UNVERIFIED |
