| UCUnion Corrugating | Ocala | FL | — | ◇ UNVERIFIED |
| UCUnion County State Pond Water Plant | Jonesboro | IL | — | ◇ UNVERIFIED |
| UMUnion Metal - Canton | Canton | OH | — | ◇ UNVERIFIED |
| UMUnion Metal Industries CORP | Canton | OH | — | ◇ UNVERIFIED |
| UPUnion Pacific | Bellwood | IL | — | ◇ UNVERIFIED |
| UPUnion Pacific Railroad | Chicago | IL | — | ◇ UNVERIFIED |
| UPUnion Partners Upx CORP Dba Lamination Specialities CORP LLC | Chicago | IL | — | ◇ UNVERIFIED |
| UTUnion Tank Car Company | East Chicago | IN | — | ◇ UNVERIFIED |
| UTUnion Tank Car CO - Valdosta Facility | Valdosta | GA | — | ◇ UNVERIFIED |
| UOUniparts Olsen, INC. | — | IA | — | ◇ UNVERIFIED |
| UMUnique Machine & Tool | Mc Kees Rocks | PA | — | ◇ UNVERIFIED |
| UMUnique Marble | Vero Beach | FL | — | ◇ UNVERIFIED |
| UMUnique Metal Fabrication INC | Phoenix | AZ | — | ◇ UNVERIFIED |
| UMUnique Metal Products LLC | Eugene | OR | — | ◇ UNVERIFIED |
| UCUni-sim Corporation | Lisbon Falls | ME | — | ◇ UNVERIFIED |
| UIUnison Industries LLC Plant 2 | Dayton | OH | — | ◇ UNVERIFIED |
| ULUnitech Lc | Salt Lake City | UT | — | ◇ UNVERIFIED |
| UAUnited Airlines Ahnoc | Arlington Heights | IL | — | ◇ UNVERIFIED |
| UAUnited Airlines, INC. | Newark | NJ | — | ◇ UNVERIFIED |
| UBUnited Bark Products | Orland | CA | — | ◇ UNVERIFIED |
| UBUnited Best Sheet Metal | Arcadia | CA | — | ◇ UNVERIFIED |
| UBUnited Biologics INC | Santa Ana | CA | — | ◇ UNVERIFIED |
| UBUnited Biologics INC | Irvine | CA | — | ◇ UNVERIFIED |
| UBUnited Building Center | Breese | IL | — | ◇ UNVERIFIED |
| UCUnited Cartage INC | Hickory Hills | IL | — | ◇ UNVERIFIED |
| UFUnited Fabrication | Salt Lake City | UT | — | ◇ UNVERIFIED |
| UIUnited Industries, INC. | Odessa | TX | — | ◇ UNVERIFIED |
| ULUnited Lighting Standards, INC. | Warren | MI | — | ◇ UNVERIFIED |
| UMUnited Machining, Inc | Sutton | MA | — | ◇ UNVERIFIED |
| UMUnited Machining, INC. | Englewood | CO | — | ◇ UNVERIFIED |
| UMUnited Mechanical & Metal Fabricators, Inc. | Union City | CA | — | ◇ UNVERIFIED |
| UMUnited Metalcraft, INC. | Marietta | GA | — | ◇ UNVERIFIED |
| UMUnited Metal Services | Houston | TX | — | ◇ UNVERIFIED |
| UMUnited Millwright LLC | Mt Zion | IL | — | ◇ UNVERIFIED |
| UMUnited Millwright LLC | Mt Zion | IL | — | ◇ UNVERIFIED |
| UMUnited Misc & Ornamental Steel INC Dba Umo Steel INC | Union City | CA | — | ◇ UNVERIFIED |
| UMUnited Misc. & Ornamental Steel, Inc. | Union City | CA | — | ◇ UNVERIFIED |
| UPUnited Panel Corporation | Cartersville | GA | — | ◇ UNVERIFIED |
| UPUnited Panel Corporation | Griffin | GA | — | ◇ UNVERIFIED |
| UPUnited Partition Systems Inc | Ontario | CA | — | ◇ UNVERIFIED |
| UPUnited Performance Metals | La Mirada | CA | — | ◇ UNVERIFIED |
| UPUnited Personnel Services, INC. | Whately | MA | — | ◇ UNVERIFIED |
| UPUnited Pipe Bending & Fabrication INC | Portland | OR | — | ◇ UNVERIFIED |
| URUnited Rentals | Elk Grove Village | IL | — | ◇ UNVERIFIED |
| USUnited Science Industries | Dix | IL | — | ◇ UNVERIFIED |
| USUnited Science Industries INC | Okawville | IL | — | ◇ UNVERIFIED |
| USUnited Scientific INC | Saint Paul | MN | — | ◇ UNVERIFIED |
| USUnited Solar Ovonic | Auburn Hills | MI | — | ◇ UNVERIFIED |
| USUnited Spring & Mfg. Co. | Chicago | IL | — | ◇ UNVERIFIED |
| USUnited Spring Technology INC | Farmington Hills | MI | — | ◇ UNVERIFIED |
| USUnited States Associates, LLC | Providence | RI | — | ◇ UNVERIFIED |
| USUnited States Mint at San Francisco | San Francisco | CA | — | ◇ UNVERIFIED |
| USUnited Steel Fabricators INC | Rialto | CA | — | ◇ UNVERIFIED |
| USUnited Steel, INC. | Wichita | KS | — | ◇ UNVERIFIED |
| USUnited Steel Products | Largo | FL | — | ◇ UNVERIFIED |
| USUnited Steel Products Company, INC. | Livermore | CA | — | ◇ UNVERIFIED |
| USUnited Steel Ventures INC Dba United Precision Mac | Edina | MN | — | ◇ UNVERIFIED |
| USUnited Steel Works, INC. | Clearwater | FL | — | ◇ UNVERIFIED |
| USUnited Steel Works, INC. | Clearwater | FL | — | ◇ UNVERIFIED |
| USUnited Structural Works, INC. | Congers | NY | — | ◇ UNVERIFIED |
| USUnited Structures of Georgia LLC | Cairo | GA | — | ◇ UNVERIFIED |
| USUnited Sugars Producers & Refiners Cooperative-chicago | Chicago | IL | — | ◇ UNVERIFIED |
| USUnited Support Solutions INC. | Totowa | NJ | — | ◇ UNVERIFIED |
| UTUnited Team Mechanical, LLC | Kaysville | UT | — | ◇ UNVERIFIED |
| UWUnited Weld Services, LLC | York | PA | — | ◇ UNVERIFIED |
| UWUnited Wire Craft, INC. | Des Plaines | IL | — | ◇ UNVERIFIED |
| U5Unity 5 INC | Deerfield | IL | — | ◇ UNVERIFIED |
| UTUnity Tool INC Dba Unity Precision Manufacturing | Maple Grove | MN | — | ◇ UNVERIFIED |
| USUnivar Solutions USA INC. | Carteret | NJ | — | ◇ UNVERIFIED |
| UCUniversal Compression INC | Tulsa | OK | — | ◇ UNVERIFIED |
 Universal Compressor Solutions LLC | Mayfield | KY | — | ◇ UNVERIFIED |
| UDUniversal Dust Collector Mfg & Supply CORP Dba Udc Corporation | Anaheim | CA | — | ◇ UNVERIFIED |
| UEUniversal Enterprises, INC. | Shinnston | WV | — | ◇ UNVERIFIED |
| UFUniversal Fabricating & Construction Ser | Columbus | OH | — | ◇ UNVERIFIED |
| UFUniversal Fabricators INC | Madison Heights | MI | — | ◇ UNVERIFIED |
| UFUniversal Fabricators, LLC | Eglin Afb | FL | — | ◇ UNVERIFIED |
| UFUniversal Formations INC | Burnsville | MN | — | ◇ UNVERIFIED |
| UHUniversal Head CO INC | Joliet | IL | — | ◇ UNVERIFIED |
| UIUniversal Iron Works, INC | Pacoima | CA | — | ◇ UNVERIFIED |
| UMUniversal Machine Shop | Huntington Beach | CA | — | ◇ UNVERIFIED |
| UMUniversal Metal Hose Company | Chicago | IL | — | ◇ UNVERIFIED |
| UMUniversal Metal Products | Pemberville | OH | — | ◇ UNVERIFIED |
| UOUniversal Ornamental Iron, INC. | Conyers | GA | — | ◇ UNVERIFIED |
| URUniversal Roll Forming INC | Lindon | UT | — | ◇ UNVERIFIED |
| USUniversal Sawmill | Bungay | IL | — | ◇ UNVERIFIED |
| USUniversal Sheetmetal INC | Woodinville | WA | — | ◇ UNVERIFIED |
| USUniversal Steel Fabricators, INC. | Brooklyn | NY | — | ◇ UNVERIFIED |
| USUniversal Steel of North Carolina, LLC | Thomasville | NC | — | ◇ UNVERIFIED |
| UTUniversal Tool, INC. | Rainbow City | AL | — | ◇ UNVERIFIED |
| UTUniversal Tool Steel LLC | Springfield | TN | — | ◇ UNVERIFIED |
| UFUniversity Frames INC | Anaheim | CA | — | ◇ UNVERIFIED |
| UPUniversity Park Golo | University Park | IL | — | ◇ UNVERIFIED |
| USUniversity Service | Decatur | IL | — | ◇ UNVERIFIED |
| UUnknown | Topeka | KS | — | ◇ UNVERIFIED |
| UIUnlimited Image INC | Burnsville | MN | — | ◇ UNVERIFIED |
| UIUnobtanium INC | Oregon City | OR | — | ◇ UNVERIFIED |
| UMUnverferth Manufacturing Company, INC - Lexington Division - South Facility | Lexington | NE | — | ◇ UNVERIFIED |
| UMUnverferth Mfg CO INC | Kalida | OH | — | ◇ UNVERIFIED |
| UMUpchurch Machine Co., INC. | Charlotte | NC | — | ◇ UNVERIFIED |
| USUpcycle Solutions, Inc. | Londonderry | NH | — | ◇ UNVERIFIED |
