| SBSouth Bay Foundry INC | Santee | CA | Primary Metal Manufacturing331513 | — | ◇ UNVERIFIED |
| SMSpace Machining INC | San Jose | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| SISparkz INC | Sacramento | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| SWSpingolo Warehouse Company | Stockton | CA | Primary Metal Manufacturing331315 | — | ◇ UNVERIFIED |
 Stang Industries INC | Corona | CA | Primary Metal Manufacturing331511 | — | ◇ UNVERIFIED |
| SMStar Metals, Inc. | Jurupa Valley | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| SFSteel Flow Corporation | San Bernardino | CA | Primary Metal Manufacturing331420 | — | ◇ UNVERIFIED |
| SGStone Gryphon Tactical LLC | Chula Vista | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| SIStrand Industries | Riverside | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| SISummit Iron Works Group INC | Gardena | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| SOSunrise of Carmichael | Carmichael | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| SISuperior Industries International INC | Van Nuys | CA | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| TPTerrycable Products | Hesperia | CA | Primary Metal Manufacturing331222 | — | ◇ UNVERIFIED |
| TAThakar Aluminum CORP | Corona | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| TBThe Buyers INC | Santa Fe Springs | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| TCThe Carlstar Group LLC | Ontario | CA | Primary Metal Manufacturing331110 | — | ▲ REPORTED CLOSED |
| TSThe Strelitz CO INC | Los Angeles | CA | Primary Metal Manufacturing331410 | — | ◇ UNVERIFIED |
| TMThorock Metals INC | Compton | CA | Primary Metal Manufacturing331314 | — | ◇ UNVERIFIED |
| TMThyssenkrupp Materials Na/ - Ken Mac Metals | Santa Fe Spgs | CA | Primary Metal Manufacturing331315 | — | ◇ UNVERIFIED |
| TSTitanium Specialties | Taft | CA | Primary Metal Manufacturing331523 | — | ◇ UNVERIFIED |
| TWTi Wire | Etiwanda | CA | Primary Metal Manufacturing331222 | — | ◇ UNVERIFIED |
| TTTotten Tubes INC - Santee | Santee | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| TTTransition45 Technologies INC | Orange | CA | Primary Metal Manufacturing331528 | — | ◇ UNVERIFIED |
| TITree Island Wire | Rancho Cucamonga | CA | Primary Metal Manufacturing331222 | — | ▲ REPORTED CLOSED |
| TITree Island Wire (usa) INC. | Walnut | CA | Primary Metal Manufacturing331422 | — | ◇ UNVERIFIED |
| TGTri-alloy Group, LLC | Montclair | CA | Primary Metal Manufacturing331312 | — | ◇ UNVERIFIED |
| TFTriangle Fasteners INC | Ontario | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| TITru-cut INC | Gardena | CA | Primary Metal Manufacturing331315 | — | ◇ UNVERIFIED |
| TSTryad Service CORP. | Shafter | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| THTubbs Holding | Sacramento | CA | Primary Metal Manufacturing331420 | — | ◇ UNVERIFIED |
| TBTube Bending Specialists & Machinery, LLC | Hayward | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| TCTusco Casting Corporation | Lodi | CA | Primary Metal Manufacturing331528 | — | ◇ UNVERIFIED |
| TBTy Bar CORP | South Gate | CA | Primary Metal Manufacturing331524 | — | ◇ UNVERIFIED |
| TNTyvak Nano Satellite Systems | Irvine | CA | Primary Metal Manufacturing331523 | — | ◇ UNVERIFIED |
| UUlbrich | Pico Rivera | CA | Primary Metal Manufacturing331221 | — | ◇ UNVERIFIED |
| UUUltra USA INC | Los Angeles | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| UAUmc Acquisition CORP | Lynwood | CA | Primary Metal Manufacturing331315 | — | ◇ UNVERIFIED |
| UAUnited Alloys INC | Los Angeles | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| UPUnited Pipe & Steel | Stockton | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| USUnited Security Product INC | Poway | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| USUnited Spiral Pipe LLC Manufacturing Plan | Pittsburg | CA | Primary Metal Manufacturing331210 | — | ◇ UNVERIFIED |
| UAUniversal Alloy Corporation | Anaheim | CA | Primary Metal Manufacturing331316 | — | ◇ UNVERIFIED |
| UDUniversal Die Casting CO | Los Angeles | CA | Primary Metal Manufacturing331522 | — | ◇ UNVERIFIED |
| UMUniversal Machine Company INC | Paramount | CA | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| UMUniversal Molding Company | Lynwood | CA | Primary Metal Manufacturing331314 | — | ◇ UNVERIFIED |
| UMUniversal Molding Company INC. | Anaheim | CA | Primary Metal Manufacturing331318 | — | ◇ UNVERIFIED |
| UPUSA Produce | Los Banos | CA | Primary Metal Manufacturing331313 | — | ◇ UNVERIFIED |
| UCUsg Ceilings Plus LLC | Commerce | CA | Nonmetallic Mineral Product Manufacturing327122 | — | ◇ UNVERIFIED |
| USU S Reduction CO | Fontana | CA | Primary Metal Manufacturing331492 | — | ◇ UNVERIFIED |
| USU S Technical Ceramics INC | Morgan Hill | CA | Primary Metal Manufacturing331311 | — | ◇ UNVERIFIED |
