| SIStiltz Iron, INC | Clarksville | TN | — | ◇ UNVERIFIED |
| SIStocklin Iron INC | Santa Rosa | CA | — | ◇ UNVERIFIED |
| SMStone Manufacturing Company | Gardena | CA | — | ◇ UNVERIFIED |
| SMStone Manufacturing Custom Handmade Fireplace Accessories LLC | Buffalo Grove | IL | — | ◇ UNVERIFIED |
| SRStones River Steel | Miboro | TN | — | ◇ UNVERIFIED |
| SSStratford Steel, LLC | Stratford | CT | — | ◇ UNVERIFIED |
| SMStrathmore Machinery INC | Strathmore | CA | — | ◇ UNVERIFIED |
| SSStretch Solutions LLC | Riverside | CA | — | ◇ UNVERIFIED |
| SCStrick Corporation | Abbeville | SC | — | ◇ UNVERIFIED |
 Strong Structural Steel, LTD | Pharr | TX | — | ◇ UNVERIFIED |
| SSStruc Steel INC | Spring Valley | CA | — | ◇ UNVERIFIED |
| SBStructall Building Systems, INC. | San Antonio | TX | — | ◇ UNVERIFIED |
| SCStructural Coatings, INC. | Clayton | NC | — | ◇ UNVERIFIED |
| SCStructural Coatings, INC. - Clayton | Clayton | NC | — | ◇ UNVERIFIED |
| SSStructural Steel Fabricators INC | Stanton | CA | — | ◇ UNVERIFIED |
| SSStructural Steel of Carolina - Hickory Steel | Hickory | NC | — | ◇ UNVERIFIED |
| SSStructural Steel Products Corporation | Clayton | NC | — | ◇ UNVERIFIED |
| SSStructural Steel Services Inc, Plant 3 | Meridian | MS | — | ◇ UNVERIFIED |
| SSStructural Steel Services, Inc., Plant 6 | Meridian | MS | — | ◇ UNVERIFIED |
| SSStructural Steel Services Inc, Plants 1 | Meridian | MS | — | ◇ UNVERIFIED |
| SSStructural Steel Services, Plant 1 | Meridian | MS | — | ◇ UNVERIFIED |
| SFStructure Fabricators | Evansville | IN | — | ◇ UNVERIFIED |
| SMStryker Metals LLC | Dayton | OH | — | ◇ UNVERIFIED |
| SStucke | Kent | WA | — | ◇ UNVERIFIED |
| SBStupp Bros INC | Richardsville | KY | — | ◇ UNVERIFIED |
| SSSuburban Steel Supply Company LLC | Gahanna | OH | — | ◇ UNVERIFIED |
| SSSukup Steel Structures LLC | Ambridge | PA | — | ◇ UNVERIFIED |
| SMSulta Manufacturing Company | Sulphur Springs | TX | — | ◇ UNVERIFIED |
| SCSulzer Chemtech Usa, INC. | Tulsa | OK | — | ◇ UNVERIFIED |
| SSSummit Steel Works CORP | San Jose | CA | — | ◇ UNVERIFIED |
| SUSummit Utility Structures, LLC | Allentown | PA | — | ◇ UNVERIFIED |
| SFSunburst Fabrications INC | Redmond | OR | — | ◇ UNVERIFIED |
| SESunrise Erectors | Canton | MA | — | ◇ UNVERIFIED |
| SMSunshine Metals | Corona | CA | — | ◇ UNVERIFIED |
| SSSun Steel Company | University Park | IL | — | ◇ UNVERIFIED |
| SSunsteel,llc | Sunnyside | WA | — | ◇ UNVERIFIED |
| SDSuper Duty, INC. | Hot Springs | AR | — | ◇ UNVERIFIED |
| SASuperior Architecture Mfg INC | Bell Gardens | CA | — | ◇ UNVERIFIED |
| SFSuperior Fabrication INC. | Canadian | TX | — | ◇ UNVERIFIED |
| SFSuperior Fabrication & Welding LLC | Punta Gorda | FL | — | ◇ UNVERIFIED |
| SISuperior Iron INC | Otsego | MN | — | ◇ UNVERIFIED |
| SMSuperior Mason Products LLC | Homewood | AL | — | ◇ UNVERIFIED |
| SMSuperior Mason Products LLC | Birmingham | AL | — | ◇ UNVERIFIED |
| SSSuperior Steel Connectors Inc | Bay Shore | NY | — | ◇ UNVERIFIED |
| SSSuperior Steel Connectors Inc | Ronkonkoma | NY | — | ◇ UNVERIFIED |
 Superior Steel Products | Kinzers | PA | — | ◇ UNVERIFIED |
| SSSuperior Suppliers Network, LLC | Houghton | MI | — | ◇ UNVERIFIED |
 Superior Tank CO INC | Rancho Cucamonga | CA | — | ◇ UNVERIFIED |
| SSSuper Steel LLC | Milwaukee | WI | — | ◇ UNVERIFIED |
| SSSuper Steel Products CORP | Milwaukee | WI | — | ◇ UNVERIFIED |
