| SISearing Ind | Rancho Cucamonga | CA | — | ◇ UNVERIFIED |
| SFSefi Fabricators; IMC Teddy; Bayone Stainless Products | Amityville | NY | — | ◇ UNVERIFIED |
| SCSequatchie Concrete Service INC | Madison | AL | — | ◇ UNVERIFIED |
| SCSequatchie Concrete Service, Inc-closed | Nashville | TN | — | ◇ UNVERIFIED |
| SCSesser Concrete Products CO | Sesser | IL | — | ◇ UNVERIFIED |
| SBSeymore Bros, INC. | Altoona | PA | — | ◇ UNVERIFIED |
| SBShaffer Block & Concrete Products | Somerset | PA | — | ◇ UNVERIFIED |
| SPShawcor Pipe Protection LLC. | Fontana | CA | — | ◇ UNVERIFIED |
| SSSheffield Steel Products INC | Macedonia | OH | — | ◇ UNVERIFIED |
 Sherman Industries,inc. | Birmingham | AL | — | ◇ UNVERIFIED |
| SMShieldalloy Metallurgical | Newfield | NJ | — | ◇ UNVERIFIED |
| SRShipping Rail Red Line | Blytheville | AR | — | ◇ UNVERIFIED |
| SCSierra Construction, INC. | Channelview | TX | — | ◇ UNVERIFIED |
| SDSigma DG Corporation Inc. | Vancouver | WA | — | ◇ UNVERIFIED |
| SCSilver Creek Stoneworks INC | Rochester | MN | — | ◇ UNVERIFIED |
| SSSims Stone CO. of Georgia, LLC | Woodbury | GA | — | ◇ UNVERIFIED |
| S3Skanska - 3 Mile Bridge Pre-cast Facility | Pensacola | FL | — | ◇ UNVERIFIED |
 Skyline Steel CORP | Brooklyn | NY | — | ◇ UNVERIFIED |
| SLSlater Lemont CORP | Lemont | IL | — | ◇ UNVERIFIED |
| SSSmi Steel Arkansas (dba Cmc Steel Ar) | Magnolia | AR | — | ◇ UNVERIFIED |
| SMSms Mill Services LLC Contractor of Ace | Burns Harbor | IN | — | ◇ UNVERIFIED |
| SMSnl-iov Montclair Owner LLC | Montclair | CA | — | ◇ UNVERIFIED |
| SBSnyder Brick and Block | Columbus | OH | — | ◇ UNVERIFIED |
| SBSnyder Brick & Block | Dayton | OH | — | ◇ UNVERIFIED |
| SISolsil Incorporated (0684000225) | Beverly | OH | — | ◇ UNVERIFIED |
| SBSouthern Block Company | Warsaw | NC | — | ◇ UNVERIFIED |
| SCSouthern Concrete Materials, INC Dba Charlotte Blo | Charlotte | NC | — | ◇ UNVERIFIED |
| SPSouthern Perfection Fabrication Holdings, INC. | Byron | GA | — | ◇ UNVERIFIED |
| SPSouthern Products | Sardis | MS | — | ◇ UNVERIFIED |
| SSSouthern Star Steel Services LLC | Lorena | TX | — | ◇ UNVERIFIED |
| SSSouthern Steel Fabricators | Metairie | LA | — | ◇ UNVERIFIED |
| SSSouthern Steel Products CO | Clarksburg | WV | — | ◇ UNVERIFIED |
| SMSouthwind Milling Company, LLC | Pine Bluff | AR | — | ◇ UNVERIFIED |
| SCSpeer Concrete, INC. | Carthage | NC | — | ◇ UNVERIFIED |
| SMSpg Mechanical | Pocatello | ID | — | ◇ UNVERIFIED |
| SCSpringfield Concrete Block & Brick, INC. | Springfield | OH | — | ◇ UNVERIFIED |
| SCSrm Concrete, Llc, Concrete Block Plant #911 | Saint Paris | OH | — | ◇ UNVERIFIED |
| SPSrm Plant 14120 Blue Wing | San Antonio | TX | — | ◇ UNVERIFIED |
| SSS & S Custom Iron Works Llc | Redmond | WA | — | ◇ UNVERIFIED |
| SSStaffing Services, INC. | Lincoln | NE | — | ◇ UNVERIFIED |
| SSStainless Steel Tanks, INC. | Saint Mary | MO | — | ◇ UNVERIFIED |
| SBStandard Block Company, Inc. | Newnan | GA | — | ◇ UNVERIFIED |
| SSStandard Supply CO | Maysville | KY | — | ◇ UNVERIFIED |
| SRState Road Cement Block | Dartmouth | MA | — | ◇ UNVERIFIED |
| SSState Steel of South Dakota, INC. | Sioux Falls | SD | — | ◇ UNVERIFIED |
| SSStation Steel Services, Inc | Milford | PA | — | ◇ UNVERIFIED |
| SMStavola Materials Oldwick Quarry | Oldwick | NJ | — | ◇ UNVERIFIED |
| SDSteel Dynamics, INC. | Lake City | FL | — | ◇ UNVERIFIED |
| SDSteel Dynamics, INC. (sdi), Structural | Columbia City | IN | — | ◇ UNVERIFIED |
| SDSteel Dynamics, INC. - Swva, INC. | Huntington | WV | — | ◇ UNVERIFIED |
