| OTOlympus Technologies Incorporated | Eugene | OR | — | ◇ UNVERIFIED |
| OOmco | Talladega | AL | — | ◇ UNVERIFIED |
| OHOmco - Huntsville | Madison | AL | — | ◇ UNVERIFIED |
| OROmco Roll Forming Plus - Wickliffe | Wickliffe | OH | — | ◇ UNVERIFIED |
| OCOmega Consolidated Corporation | Hilton | NY | — | ◇ UNVERIFIED |
| OMOmega Machine & Tool, INC. | Mentor | OH | — | ◇ UNVERIFIED |
| OSOmega Steel Products, INC | Jemison | AL | — | ◇ UNVERIFIED |
| OTOmega Tool CO | Saint Louis | MO | — | ◇ UNVERIFIED |
| OMO & M Fabricators, LLC | Pensacola | FL | — | ◇ UNVERIFIED |
| OIOmg, INC. Dba Hickman Engineered Systems | Arden | NC | — | ◇ UNVERIFIED |
| OTOmk Tube Miller Rd 2 | Houston | TX | — | ◇ UNVERIFIED |
| OMOm Machine & Tool LLC | Portland | OR | — | ◇ UNVERIFIED |
| OOmniduct | Everett | WA | — | ◇ UNVERIFIED |
| OAOmniduct Arlington | Arlington | WA | — | ◇ UNVERIFIED |
| OAOmniduct Az, LLC | Phoenix | AZ | — | ◇ UNVERIFIED |
| OIOmni Industrial Services | Buffalo | WV | — | ◇ UNVERIFIED |
| OOmnimax | Gridley | IL | — | ◇ UNVERIFIED |
| OIOmnimax International, INC. | Ivyland | PA | — | ◇ UNVERIFIED |
| OIOmnimax International, LLC Dba Millennium Metals | Jacksonville | FL | — | ◇ UNVERIFIED |
| OMOmni Measurement Systems | Winooski | VT | — | ◇ UNVERIFIED |
| OPOmni Precision | Houston | TX | — | ◇ UNVERIFIED |
| OPOmni Precision, INC. | Houston | TX | — | ◇ UNVERIFIED |
| ODOn Demand Edm INC | Blaine | MN | — | ◇ UNVERIFIED |
| OTOneida Tool Corporation | Redford | MI | — | ◇ UNVERIFIED |
| OMOneto Metal Products CORP | Sacramento | CA | — | ◇ UNVERIFIED |
| OTOne Ton Welding, Inc. | Panama | IA | — | ◇ UNVERIFIED |
| OAOnex Automation | Duarte | CA | — | ◇ UNVERIFIED |
| OSOney Sheetmetal INC | Fort Myers | FL | — | ◇ UNVERIFIED |
| OCOnsite Calibartion Service INC | Louisville | KY | — | ◇ UNVERIFIED |
| OSOn Spot Portable Machine CO INC | Livonia | MI | — | ◇ UNVERIFIED |
 On The Edge MFG, Inc | Kittanning | PA | — | ◇ UNVERIFIED |
| OTOn the Mean, Machine, LLC | Grand Rapids | OH | — | ◇ UNVERIFIED |
| OTOn Time Fab INC | Saint Joseph | KY | — | ◇ UNVERIFIED |
| OFOostman Fabricating & Welding, INC. | Westmont | IL | — | ◇ UNVERIFIED |
| OFOpc Fabrication and Equipment, INC. (fn) | Phoenix | AZ | — | ◇ UNVERIFIED |
| OOOpEx OpCo Inc. | Minneapolis | MN | — | ◇ UNVERIFIED |
| OIOPMP, Inc. | Tracy | CA | — | ◇ UNVERIFIED |
| OPOptima Precision, Inc. | San Jose | CA | — | ◇ UNVERIFIED |
| OPOptimum Parts Company | Holyoke | MA | — | ◇ UNVERIFIED |
| OSOrange State Steel | Bartow | FL | — | ◇ UNVERIFIED |
| OSOrange State Steel Construction, INC. | Riverview | FL | — | ◇ UNVERIFIED |
| OSOrange Steel Roofing Products | Orange | VA | — | ◇ UNVERIFIED |
| OCOrco Construction Supply | Bloomington | CA | — | ◇ UNVERIFIED |
| ODOreco Duct System INC | Baldwin Park | CA | — | ◇ UNVERIFIED |
| OIOregon Industrial Repair INC | Salem | OR | — | ◇ UNVERIFIED |
| OMOregon Machine Works, INC. | Canby | OR | — | ◇ UNVERIFIED |
| OPOregon Pacific Structural Fabrication, LLC | Mulino | OR | — | ◇ UNVERIFIED |
| OSOreland Sheet Metal Inc | Huntingdon Valley | PA | — | ◇ UNVERIFIED |
| OTOrganic Transit INC. | Durham | NC | — | ◇ UNVERIFIED |
| OEOri Enterprises LLC | Price | UT | — | ◇ UNVERIFIED |
| OEOriginal Exhaust Manufacturers INC | Hopkinsville | KY | — | ◇ UNVERIFIED |
| OEOrion Enterprises INC | Kansas City | KS | — | ◇ UNVERIFIED |
| OPOrion Properties Group LLC | New Prague | MN | — | ◇ UNVERIFIED |
| OIOrlando Iron Works | Paterson | NJ | — | ◇ UNVERIFIED |
| OIOrluck Industries INC | Otsego | MN | — | ◇ UNVERIFIED |
| ODOrnalux Design Company, INC. | Oakland | CA | — | ◇ UNVERIFIED |
| OCOrrbilt Compressors, INC. | Atlanta | GA | — | ◇ UNVERIFIED |
| OWOsborne Welding, INC. | Hampton | VA | — | ◇ UNVERIFIED |
| OMOscar Macias and Sandra L. Macias | Gilroy | CA | — | ◇ UNVERIFIED |
| OAOshkosh Aerotech - Jetway Systems | Ogden | UT | — | ◇ UNVERIFIED |
| OMO&S Machine Shop, LLC | Latrobe | PA | — | ◇ UNVERIFIED |
| OIOssi's Iron Works | Las Vegas | NV | — | ◇ UNVERIFIED |
| OIOutlaw Industries, LLC | Clinton | LA | — | ◇ UNVERIFIED |
| OTOutlook Tool, Inc. | Dayton | OH | — | ◇ UNVERIFIED |
| OTOutlook Tool, Inc. | Dayton | OH | — | ◇ UNVERIFIED |
| OUOver Under Real Estate, LLC | Riverton | NJ | — | ◇ UNVERIFIED |
| OMOviso Mfg | Fremont | CA | — | ◇ UNVERIFIED |
| OMOwens Machine & Manufacturing | Abilene | TX | — | ◇ UNVERIFIED |
| OPOwens Precision | Carson City | NV | — | ◇ UNVERIFIED |
| OPOwens Precision, INC. | Mound House | NV | — | ◇ UNVERIFIED |
| OSOwens & Sons, INC. | Metairie | LA | — | ◇ UNVERIFIED |
| OBOzark Barge & Dock Service Inc.* | Gravois Mills | MO | — | ◇ UNVERIFIED |
| PPPablo Precision | Oakland Park | FL | — | ◇ UNVERIFIED |
| PSPacesetter Safety, Inc. | Santa Clarita | CA | — | ◇ UNVERIFIED |
| PAPacific Air Cargo Transfer Systems, Inc | Auburn | WA | — | ◇ UNVERIFIED |
| PBPacific Bend | Hemet | CA | — | ◇ UNVERIFIED |
| PDPacific Duct INC | Montclair | CA | — | ◇ UNVERIFIED |
| PEPacific Embedment Products | Adelanto | CA | — | ◇ UNVERIFIED |
| PFPacific Fabrication INC | Rancho Cucamonga | CA | — | ◇ UNVERIFIED |
| PMPacific Metal Fab LLC | Eugene | OR | — | ◇ UNVERIFIED |
| PMPacific Metal Fabricators | Stockton | CA | — | ◇ UNVERIFIED |
| PRPacific Rebar INC | Ontario | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Livermore | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Bloomington | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Napa | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Benicia | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Stockton | CA | — | ◇ UNVERIFIED |
| PSPacific Steel Group | Bloomington | CA | — | ◇ UNVERIFIED |
| PSPacific Swiss & Manufacturing, Inc. | Tempe | AZ | — | ◇ UNVERIFIED |
| PTPacific Tool, Inc. | Redmond | WA | — | ◇ UNVERIFIED |
| PWPacific Welding Services | Asan | GU | — | ◇ UNVERIFIED |
| POPackage One, INC. | Schenectady | NY | — | ◇ UNVERIFIED |
| PDPackaging Dynamics LTD | Bohemia | NY | — | ◇ UNVERIFIED |
| PTPac Tec, LLC | Milton | WI | — | ◇ UNVERIFIED |
| PFPainted Feather Precision LLC | Ramsey | MN | — | ◇ UNVERIFIED |
| PMPaladin Manufacturing LLP | Marietta | OK | — | ◇ UNVERIFIED |
| PSPalatka Sheet Metal, INC. | Palatka | FL | — | ◇ UNVERIFIED |
| PPPalese Proto Tech, INC. | Tucson | AZ | — | ◇ UNVERIFIED |
| PMPalex Metals INC | Santa Clara | CA | — | ◇ UNVERIFIED |
| PMPalladino Metal Fabrication, INC. | Pottstown | PA | — | ◇ UNVERIFIED |
