 Skyline Steel Berkeley Facility | Huger | SC | — | ◇ UNVERIFIED |
| Skyline Steel INC. | San Francisco | CA | — | ◇ UNVERIFIED |
| Skyline Steel, INC. | Chandler | AZ | — | ◇ UNVERIFIED |
| SWSleeper Welding | Belmont | NH | — | ◇ UNVERIFIED |
| SLSmart Laser & Manufacturing LLC | Forney | TX | — | ◇ UNVERIFIED |
| SSSmede-son Steel & Building Supply Company | Brighton | MI | — | ◇ UNVERIFIED |
| SISme Industries, INC. | Las Vegas | NV | — | ◇ UNVERIFIED |
| SISme Industries, Incorporated | West Jordan | UT | — | ◇ UNVERIFIED |
| SSSme Steel | Pocatello | ID | — | ◇ UNVERIFIED |
| SSSme Steel Contractors, INC. | West Jordan | UT | — | ◇ UNVERIFIED |
| SSSme Steel Fabrication | West Jordan | UT | — | ◇ UNVERIFIED |
| SJSmi Joist Sc | Eastover | SC | — | ◇ UNVERIFIED |
| SSSmi Steel Fabricators, INC. Dba Cmc Rebar-orlando | Kissimmee | FL | — | ◇ UNVERIFIED |
| SASmith Architectural Metals, LLC | Greensboro | NC | — | ◇ UNVERIFIED |
| SASmith Art Conservation LLC | Los Angeles | CA | — | ◇ UNVERIFIED |
 Smith Ironworks of Atlanta | Atlanta | GA | — | ◇ UNVERIFIED |
| SISmithworks Iron and Design Inc. | Decatur | GA | — | ◇ UNVERIFIED |
| SISmithworks Iron & Design, Inc. | Decatur | GA | — | ◇ UNVERIFIED |
| SMS & M Steel Fab INC | Beaverton | OR | — | ◇ UNVERIFIED |
| SMSmyth Metal Works LLC | Montpelier | VT | — | ◇ UNVERIFIED |
| SMSnell Manufacturing, LLC | Cottontown | TN | — | ◇ UNVERIFIED |
| SVSnell Ventures, LLC | Bradford | TN | — | ◇ UNVERIFIED |
| SSSo-cal Structural Steel Fabrication INC | Marina Del Rey | CA | — | ◇ UNVERIFIED |
| SISoelzer, INC Dba Firestone Fabricators | Signal Hill | CA | — | ◇ UNVERIFIED |
| SOSolar of Michigan | Coopersville | MI | — | ◇ UNVERIFIED |
| SISolher Iron, Inc. | San Francisco | CA | — | ◇ UNVERIFIED |
| SFSolid Form Fabrication INC | Mcminnville | OR | — | ◇ UNVERIFIED |
| SRSolid Rock Gate Supply, INC Dba Welding Fabrication Services | Post Falls | ID | — | ◇ UNVERIFIED |
| SFSomerville Fabricators, INC | Mineral Wells | WV | — | ◇ UNVERIFIED |
| SSSonne Steel INC | Smithfield | KY | — | ◇ UNVERIFIED |
| SSSonne Steel INC. | Smithfield | KY | — | ◇ UNVERIFIED |
| SWSonoma Welding & Fabrication LLC | Cape May | NJ | — | ◇ UNVERIFIED |
| SCSonoran Capital Group, INC. | Tucson | AZ | — | ◇ UNVERIFIED |
| SSSopris Steel Construction, Inc. | New Castle | CO | — | ◇ UNVERIFIED |
| SASousa and Demayo INC | North Attleboro | MA | — | ◇ UNVERIFIED |
| SASouth Anna Stair and Rail Company INC | Ashland | VA | — | ◇ UNVERIFIED |
| SASouth Anna Stair & Rail | Norfolk | VA | — | ◇ UNVERIFIED |
| SBSouth Bay Iron, INC | Buena Park | CA | — | ◇ UNVERIFIED |
| SCSouth Central Steel Inc. | Harpersville | AL | — | ◇ UNVERIFIED |
| SCSouth Coast Commercial | San Diego | CA | — | ◇ UNVERIFIED |
| SCSouth County Steel, INC. | West Kingston | RI | — | ◇ UNVERIFIED |
| SCSoutheastern Container | Gautier | MS | — | ◇ UNVERIFIED |
| SMSoutheastern Metal Fabricator | Rockland | MA | — | ◇ UNVERIFIED |
| SPSoutheastern Plateworks | Birmingham | AL | — | ◇ UNVERIFIED |
| SUSoutheastern Unipole INC | Bowling Green | KY | — | ◇ UNVERIFIED |
| SFSoutheast Fabricating, INC. | Cape Girardeau | MO | — | ◇ UNVERIFIED |
| SMSoutheast Mechanical Contractors | West Park | FL | — | ◇ UNVERIFIED |
| SASouthern Aluminum Finishing D.b.a. Saf Metal Fab | Atlanta | GA | — | ◇ UNVERIFIED |
| SASouthern Aluminum Finishing D.b.a. Saf Metal Fab | Villa Rica | GA | — | ◇ UNVERIFIED |
| SBSouthern Boiler Service INC. | Lakeland | FL | — | ◇ UNVERIFIED |
