| HNH.W. Nicholson Welding & Mfg. Inc. | Apollo | PA | 20–99 | ◐ LIKELY ACTIVE |
| HTH&W Tool Co., Inc | Dover | NJ | 20–99 | ◐ LIKELY ACTIVE |
| HPHye Precision Fab INC. | Anaheim | CA | — | ◐ LIKELY ACTIVE |
| HIHyPro Inc. Jefferson (JF) | Waterford | WI | 20–99 | ◐ LIKELY ACTIVE |
| HIHyPro Inc. Platteville (PT) | Platteville | WI | 20–99 | ◐ LIKELY ACTIVE |
| IAI Am Machining LLC | Albuquerque | NM | — | ◐ LIKELY ACTIVE |
| IIIbis Industries, INC. | Santa Ana | CA | — | ◐ LIKELY ACTIVE |
| IUICBiomedical US, LLC | Cartersville | GA | 20–99 | ◐ LIKELY ACTIVE |
| IMIckler Manufacturing LLC | Mooresville | NC | — | ◐ LIKELY ACTIVE |
| IPIcon Protection 62B Green Mountain Rd. | Hazle Twp. | PA | 20–99 | ◐ LIKELY ACTIVE |
| IFIDI Fabrication, Inc. d.b.a. The Gund Company Inc. Noblesville | Noblesville | IN | 1–19 | ◐ LIKELY ACTIVE |
| IIIDM- I do machining | Elmira | NY | 20–99 | ◐ LIKELY ACTIVE |
| ITIDT Tools | Frankfort | KY | 20–99 | ◐ LIKELY ACTIVE |
| IMIKO Metals USA, Inc. | Ennis | TX | 20–99 | ◐ LIKELY ACTIVE |
| IIIKS Industries, Inc. | Park Falls | WI | 20–99 | ◐ LIKELY ACTIVE |
| IPIlam Precision INC | San Jose | CA | — | ◐ LIKELY ACTIVE |
| IMIMETCO / Merchant Evans | Burlington | NJ | 20–99 | ◐ LIKELY ACTIVE |
| IEImpres Engineering Services, LLC | Holland | MI | — | ◐ LIKELY ACTIVE |
| IHIMR - Hayden | North Vernon | IN | 20–99 | ◐ LIKELY ACTIVE |
| IMIncremental Machine LLC | Baltimore | MD | — | ◐ LIKELY ACTIVE |
| IWIndependent Welding & Machine LLC | Cocoa | FL | — | ◐ LIKELY ACTIVE |
Industrial Automation LLC - Alabama | Montgomery | AL | 1–19 | ◐ LIKELY ACTIVE |
| ICIndustrial Consortium INC | Lancaster | PA | — | ◐ LIKELY ACTIVE |
| IDIndustrial Design Manufacturing LLC | Mount Sterling | KY | — | ◐ LIKELY ACTIVE |
| IEIndustrial Engineering Manufacturing Co, INC | Foxboro | MA | — | ▲ REPORTED CLOSED |
| ITIndustrial Tank & Containment INC | Brookfield | OH | — | ◐ LIKELY ACTIVE |
| ITIndustrial Technologies Group ITG CA Design Raleigh | Raleigh | NC | 20–99 | ◐ LIKELY ACTIVE |
| ITIndustrial Technologies Group ITG Field Controls | Kinston | NC | 100–499 | ◐ LIKELY ACTIVE |
| ITIndustrial Technologies Group ITG Precision Engineering | Uxbridge | MA | 20–99 | ◐ LIKELY ACTIVE |
| ITIndustrial Technologies Group ITG WakefieldNashua | Nashua | NH | 100–499 | ◐ LIKELY ACTIVE |
| ITInlet Tools, INC | Conneautville | PA | — | ◐ LIKELY ACTIVE |
| IFInnovation First Manufacturing, Inc. | Greenville | TX | 20–99 | ◐ LIKELY ACTIVE |
| IEInnovative Engineered Solutions | Wilmington | OH | 20–99 | ◐ LIKELY ACTIVE |
| IDInrock Drilling Systems | Houston | TX | 20–99 | ◐ LIKELY ACTIVE |
| IFIntegral Fabrication & Engineering, LLC | Orlando | FL | — | ◐ LIKELY ACTIVE |
| IMIntegrated Machining CO | Albuquerque | NM | — | ◐ LIKELY ACTIVE |
| IMIntegrated Machining Solutions INC | Norwalk | CA | — | ◐ LIKELY ACTIVE |
| IIIntegration INC | Albuquerque | NM | — | ◐ LIKELY ACTIVE |
| IEIntegrity Engineering Holding, Inc | Ramsey | MN | 20–99 | ◐ LIKELY ACTIVE |
| IMIntegrity Machining, INC | Augusta | IL | — | ◐ LIKELY ACTIVE |
| ITIntegrity Tank Service, LLC | Henderson | KY | 1–19 | ◐ LIKELY ACTIVE |
| IVIntellectual Ventures Property Holdings LLC | Bellevue | WA | — | ◐ LIKELY ACTIVE |
| ISIntellifab Solutions LLC | Atlanta | GA | — | ◐ LIKELY ACTIVE |
| IMInter-city Manufacturing, INC. | Seaside | CA | — | ◐ LIKELY ACTIVE |
International Computer Appliances Corporation | Minneapolis | MN | 100–499 | ◐ LIKELY ACTIVE |
| IQInternational Quality Advantage LLC | Windsor Mill | MD | — | ◐ LIKELY ACTIVE |
International Tool and Manufacturing, INC | Fairfield | NJ | — | ◐ LIKELY ACTIVE |
| IDir Distributers D. B. A. The Metal Shop | Dunnellon | FL | 20–99 | ◐ LIKELY ACTIVE |
| IMIsland Machine, INC | Everett | WA | — | ◐ LIKELY ACTIVE |
| ICItech Custom Manufacturing and Design INC. | Riviera Beach | FL | — | ◐ LIKELY ACTIVE |