| SSSigma Steel Incorporated | Bedford | IN | — | ◇ UNVERIFIED |
| SCSignature Craft, LLC | Saint Louis | MO | — | ◇ UNVERIFIED |
| SFSignature Finishers | Cordele | GA | — | ◇ UNVERIFIED |
| SCSilgan Containers Manufac CORP | Kingsburg | CA | — | ◇ UNVERIFIED |
| SSSilver Star Manufacturing LLC | Brainerd | MN | — | ◇ UNVERIFIED |
| SESilvz Equipment LLC | Tempe | AZ | — | ◇ UNVERIFIED |
| SISimko Industrial Fabricators | Hammond | IN | — | ◇ UNVERIFIED |
| SSSimmons Stairways INC. | San Jose | CA | — | ◇ UNVERIFIED |
| SPSimple Pulse LLC | Monroe | OR | — | ◇ UNVERIFIED |
| SCSimplex Construction Supplies | Blaine | MN | — | ◇ UNVERIFIED |
| SMSimply Mfg (former) | Prairie Du Sac | WI | — | ◇ UNVERIFIED |
| SSSimpson Strong Tie | Riverside | CA | — | ◇ UNVERIFIED |
| SSSimpson Strong Tie CORP | Stockton | CA | — | ◇ UNVERIFIED |
| SMSincere Metal Works | Amesbury | MA | — | ◇ UNVERIFIED |
| SISindr Industries Inc | Mt Clemens | MI | — | ◇ UNVERIFIED |
| SESinger Equities INC Dba Triad Bellows Design & Mfg | Anaheim | CA | — | ◇ UNVERIFIED |
| SSSingle Source INC | Tallahassee | FL | — | ◇ UNVERIFIED |
| SISitemaster, INC. | Slidell | LA | — | ◇ UNVERIFIED |
| SRSite Resources, LLC | Raleigh | NC | — | ◇ UNVERIFIED |
| SCSix C Fabrication INC | Winnfield | LA | — | ◇ UNVERIFIED |
| SLSjjr, LLC | Taunton | MA | — | ◇ UNVERIFIED |
| SISkaggs Iron Works, INC. | Memphis | TN | — | ◇ UNVERIFIED |
| SKS & K Machineworks Company, INC. | Theodore | AL | — | ◇ UNVERIFIED |
| SCSkrlin Coating & Blasting INC. | Niagara Falls | NY | — | ◇ UNVERIFIED |
| SDSkycomm Development, INC | Helena | MT | — | ◇ UNVERIFIED |
 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 |
| SCSmith Center Plant 1 | Smith Center | KS | — | ◇ 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 |
| SWSnow Wheel System INC | Fairmont | MN | — | ◇ UNVERIFIED |
| SSSo-cal Structural Steel Fabrication INC | Marina Del Rey | CA | — | ◇ UNVERIFIED |
