| RFRmg Foundry | Mishawaka | IN | — | ◇ UNVERIFIED |
| RMR M Masonry | Richmond | VA | — | ◇ UNVERIFIED |
| RFRobinson Foundry INC | Alexander City | AL | — | ◇ UNVERIFIED |
| RCRockbridge Castings | Rockbridge | IL | — | ◇ UNVERIFIED |
| RCRoss Cast Metals | Lancaster | OH | — | ◇ UNVERIFIED |
| RSRoss Sand Casting Industries, Inc., Plan | Winchester | IN | — | ◇ UNVERIFIED |
| RSRoss Sand Casting Industry, LLC | Orrville | OH | — | ◇ UNVERIFIED |
| SCSanders CO INC | Elizabeth City | NC | — | ◇ UNVERIFIED |
| SISandwich Iron Foundry | Plano | IL | — | ◇ UNVERIFIED |
| SMSather Mfg CO INC | Everett | WA | — | ◇ UNVERIFIED |
 Schuff Steel Company | Salt Lake City | UT | — | ◇ UNVERIFIED |
| SFSchwarb Foundry | Warren | MI | — | ◇ UNVERIFIED |
| SISchwarb Industries INC | Troy | MI | — | ◇ UNVERIFIED |
| SEScott Engineering and Procurement, INC. (1431004456) | Loveland | OH | — | ◇ UNVERIFIED |
| SFSeaboard Foundry | Johnston, Town of | RI | — | ◇ UNVERIFIED |
| SBSequoia Brick | Lindsay | CA | — | ◇ UNVERIFIED |
| SBService Brass & Aluminum Foundry, INC. | Wichita | KS | — | ◇ UNVERIFIED |
| SESewer Equipment CO. of Florida, INC. | New Smyrna Beach | FL | — | ◇ UNVERIFIED |
| SFShelco Foundries Div of Gnutti Cado USA | Jacksonville | AL | — | ◇ UNVERIFIED |
| SFSherman Foundry | Sherman | TX | — | ◇ UNVERIFIED |
| SMSimonz Machine Dba Hyve Technologies | San Diego | CA | — | ◇ UNVERIFIED |
| SHSlack Horner Foundry | Longmont | CO | — | ◇ UNVERIFIED |
| SMSlinger Manufacturing CO INC | Slinger | WI | — | ◇ UNVERIFIED |
| SMSlinger Mfg CO INC Plant 1 | Slinger | WI | — | ◇ UNVERIFIED |
| SFSmith Foundry Company | Minneapolis | MN | — | ◇ UNVERIFIED |
| SCSomerset Consolidate/somerset | Somerset | PA | — | ◇ UNVERIFIED |
| SSSo Safe Equipment | Motley | MN | — | ◇ UNVERIFIED |
| SCSouthern Cast INC. | Charlotte | NC | — | ◇ UNVERIFIED |
| SFSpanish Fork Metals | Spanish Fork | UT | — | ◇ UNVERIFIED |
| SFSparta Foundry INC | Sparta | MI | — | ◇ UNVERIFIED |
| SFSpecialty Foundry | Brockton | MA | — | ◇ UNVERIFIED |
| SFSpecified Fittings INC | Bellingham | WA | — | ◇ UNVERIFIED |
| SFSpitz Foundry INC | Hastings | NE | — | ◇ UNVERIFIED |
| SCSpring City Elec/spring City | Spring City | PA | — | ◇ UNVERIFIED |
| SISpringfield Iron Works INC | Chicopee | MA | — | ◇ UNVERIFIED |
 Stang Industries INC | Corona | CA | — | ◇ UNVERIFIED |
| SLState Line Foundries INC | Roscoe | IL | — | ◇ UNVERIFIED |
| SFStaver Foundry CO | Virginia | MN | — | ◇ UNVERIFIED |
| SCSterling Casting | Bluffton | IN | — | ◇ UNVERIFIED |
| STStreuter Technologies INC | San Clemente | CA | — | ◇ UNVERIFIED |
| SFSturgis Foundry Corporation | Sturgis | MI | — | ◇ UNVERIFIED |
| SMSupervac Manuf. | Broomfield | CO | — | ◇ UNVERIFIED |
| SCSynehi Casting | Greenwood | SC | — | ◇ UNVERIFIED |
| TCTalladega Castings & Machine CO INC | Talladega | AL | — | ◇ UNVERIFIED |
| TFT&b Foundry Company | Cleveland | OH | — | ◇ UNVERIFIED |
| TFTexas Foundaries | Lufkin | TX | — | ◇ UNVERIFIED |
| TOTexas Outdoor Cookers, LLC | Willow City | TX | — | ◇ UNVERIFIED |
| TBThe Blanchester Foundry CO | Blanchester | OH | — | ◇ UNVERIFIED |
| TFThe Foundry INC | Mead | WA | — | ◇ UNVERIFIED |
| TGThe General Casting Company - Toledo Street | Delaware | OH | — | ◇ UNVERIFIED |
| TSThe Shredder Company | Canutillo | TX | — | ◇ UNVERIFIED |
| TPThreaded Products CO | Richmond | MI | — | ◇ UNVERIFIED |
| TPThreaded Products CO | Richmond | MI | — | ◇ UNVERIFIED |
| TBThunder Bay Foundry | Alpena | MI | — | ◇ UNVERIFIED |
| TFTomahawk Foundary, INC | Rice Lake | WI | — | ◇ UNVERIFIED |
| TKTool King INC | Wheeling | IL | — | ◇ UNVERIFIED |
 Travis Pattern Foundry | Spokane Valley | WA | — | ◇ UNVERIFIED |
| TITree Island Steel Dba Tree Island Wire USA INC | San Bernardino | CA | — | ◇ UNVERIFIED |
| TFTroy Foundry (screening Plant) | Adger | AL | — | ◇ UNVERIFIED |
| TPTyler Pipe CO | Tyler | TX | — | ◇ UNVERIFIED |
| UEUnion Electric Akers | Avonmore | PA | — | ◇ UNVERIFIED |
| USUnited States Pipe and Foundry Company Dba U.s. Pi | Union City | CA | — | ◇ UNVERIFIED |
| USUnited States Pipe & Foundry Company LLC | Naperville | IL | — | ◇ UNVERIFIED |
| UDU.s. Department of Labor-osha | Red Bud | IL | — | ◇ UNVERIFIED |
| UDUS Dol Osha Fort Lauderdale Ao | Medley | FL | — | ◇ UNVERIFIED |
| UOUsdol Osha - (mobile) | Phenix City | AL | — | ◇ UNVERIFIED |
| UOUsdol Osha- North Aurora | South Beloit | IL | — | ◇ UNVERIFIED |
| UOUsdol Osha- North Aurora | Galena | IL | — | ◇ UNVERIFIED |
| USU S Foundry & Manufacturing | Tampa | FL | — | ◇ UNVERIFIED |
| UCUsg Ceilings Plus LLC | Commerce | CA | — | ◇ UNVERIFIED |
| ULUS Lock & Hdwr Co/columbia | Columbia | PA | — | ◇ UNVERIFIED |
| UHUsp Holdings INC | Warren | OR | — | ◇ UNVERIFIED |
| UPU.s. Pipe Fabrication | Olivehurst | CA | — | ◇ UNVERIFIED |
| UPUS Pipe & Foundry CO | Birmingham | AL | — | ◇ UNVERIFIED |
| USU S Pipe & Foundry Company INC | Burlington Township | NJ | — | ◇ UNVERIFIED |
| USUS Steel - Ambridge | Ambridge | PA | — | ◇ UNVERIFIED |
| VVValley / Vulcan Mold CO | Trenton | MI | — | ◇ UNVERIFIED |
| VIVaricast INC | Vancouver | WA | — | ◇ UNVERIFIED |
| VIVermilion Iron Works | Hoopeston | IL | — | ◇ UNVERIFIED |
| VCVermont Castings | Randolph | VT | — | ◇ UNVERIFIED |
| VCVictaulic CO Amer/allentown Facility | Allentown | PA | — | ◇ UNVERIFIED |
| VCVictaulic Co/lawrenceville Plt | Tioga | PA | — | ◇ UNVERIFIED |
| VPViking Pump Inc-alloys Foundry | Cedar Falls | IA | — | ◇ UNVERIFIED |
| VMVilter Manufacturing Corporation - Milwaukee | Milwaukee | WI | — | ◇ UNVERIFIED |
| VMVirginia Metalcrafters INC | Waynesboro | VA | — | ◇ UNVERIFIED |
| WMWa317943601 - Mackenzie Castings LLC | Arlington | WA | — | ◇ UNVERIFIED |
| WDWa317945207 - D&l Foundry INC | Moses Lake | WA | — | ◇ UNVERIFIED |
| WMWalker Machine and Foundry | Roanoke | VA | — | ◇ UNVERIFIED |
| WMWard Manufacturing, LLC | Blossburg | PA | — | ◇ UNVERIFIED |
| WFWaterman Foundry | Exeter | CA | — | ◇ UNVERIFIED |
| WFWatsontown Foundry | Watsontown | PA | — | ◇ UNVERIFIED |
| WAWaunakee Alloy Casting Corporation | Waunakee | WI | — | ◇ UNVERIFIED |
 Waupaca Foundry | Tell City | IN | — | ◇ UNVERIFIED |
| Waupaca Foundry INC. | Tioga | PA | — | ◇ UNVERIFIED |
| Waupaca Foundry INC Warehouse | Waupaca | WI | — | ◇ UNVERIFIED |
| Waupaca Foundry Landfill | Waupaca | WI | — | ◇ UNVERIFIED |
| WWelaco | Bakersfield | CA | — | ◇ UNVERIFIED |
| WCWesgo Ceramics | Belmont | CA | — | ◇ UNVERIFIED |
| WCWestern Castings Company | Santa Clara | CA | — | ◇ UNVERIFIED |
| WMWestern Metals Recycling, LLC | Pueblo | CO | — | ◇ UNVERIFIED |
