| IFImperial Fabricating INC. (closed) | Madison | TN | — | ◇ UNVERIFIED |
| IIIncom, INC. | Kailua Kona | HI | — | ◇ UNVERIFIED |
| ISIndependent Steel LLC | Manassas | VA | — | ◇ UNVERIFIED |
| ISIndiana Steel and Engineering Corporation | Bedford | IN | — | ◇ UNVERIFIED |
| ICIndustrial Contractors | Evansville | IN | — | ◇ UNVERIFIED |
| IDIndustrial Design Fabrication & Installation, INC. | Sioux City | IA | — | ◇ UNVERIFIED |
| IFIndustrial Fabrication Services INC | Lake Crystal | MN | — | ◇ UNVERIFIED |
| IFIndustrial Fabrication Services INC | Lake Crystal | MN | — | ◇ UNVERIFIED |
| IFIndustrial Fabricators | Gastonia | NC | — | ◇ UNVERIFIED |
| IFIndustrial Fabricators INC. | Gastonia | NC | — | ◇ UNVERIFIED |
| IFIndustrial Fabricators, INC - Vc Plant | Gastonia | NC | — | ◇ UNVERIFIED |
| IFIndustrial Fabricators of Virgina INC | Verona | VA | — | ◇ UNVERIFIED |
| IFIndustrial Fabricators of Virginia INC | Fishersville | VA | — | ◇ UNVERIFIED |
| IMIndustrial Machine & Mfg CO | South El Monte | CA | — | ◇ UNVERIFIED |
| IMIndustrial Manufacturing and Installations, Inc | Sedalia | CO | — | ◇ UNVERIFIED |
| IPIndustrial Plating & Machine, INC. | Bluefield | WV | — | ◇ UNVERIFIED |
| IPIndustrial Precision Coatings INC | Randolph | MA | — | ◇ UNVERIFIED |
| ISIndustrial Sheetmetal & Fabricators, INC. | Vidor | TX | — | ◇ UNVERIFIED |
| ISIndustrial Steel Construction Incorporated | Gary | IN | — | ◇ UNVERIFIED |
| ISIndustrial Steel Fabrication, Incorporated | Hazelwood | MO | — | ◇ UNVERIFIED |
| ISIndustrial Steel Fabricators, INC. | Jacksonville | FL | — | ◇ UNVERIFIED |
 Industrial Tool & Die Co., INC. | Harlingen | TX | — | ◇ UNVERIFIED |
| ITIndustrial Toolz INC | Kenosha | WI | — | ◇ UNVERIFIED |
| ICInfra-metals CO. | Marseilles | IL | — | ◇ UNVERIFIED |
| ILInnofab LLC | Milwaukee | WI | — | ◇ UNVERIFIED |
| IIInnovative Industrial | Brownsville | TX | — | ◇ UNVERIFIED |
| IIInnovative Industrial Fabricators LLC | Keithville | LA | — | ◇ UNVERIFIED |
| ISIn Stainless Steel Specialist | Hampden | ME | — | ◇ UNVERIFIED |
| ICInsulated Component Structures of Fl, INC. | Eustis | FL | — | ◇ UNVERIFIED |
| IMIntegrated Mechanical INC | Albany | OR | — | ◇ UNVERIFIED |
| ISIntegrated Steel | Brooksville | FL | — | ◇ UNVERIFIED |
| ITIntegrated Tower Systems | Tulsa | OK | — | ◇ UNVERIFIED |
| ITIntegrity Tool INC. | Ontario | NY | — | ◇ UNVERIFIED |
| IFIntelligent Fixtures | El Monte | CA | — | ◇ UNVERIFIED |
| ISIntelligent Steel Solutions, L.l.c. | New Orleans | LA | — | ◇ UNVERIFIED |
| ISInternational Steel & Counterweights LLC | Youngstown | OH | — | ◇ UNVERIFIED |
| ISInternational Steel Framing | League City | TX | — | ◇ UNVERIFIED |
| IFIntersteel Fabrication INC | Louisville | KY | — | ◇ UNVERIFIED |
| ISIntl Special Attractions LLC | Puyallup | WA | — | ◇ UNVERIFIED |
| IGIntricate Grinding & Machine Specialties | Norton Shores | MI | — | ◇ UNVERIFIED |
| IKIpsco Koppel Tubulars Llc/koppel Plt | Koppel | PA | — | ◇ UNVERIFIED |
| IOIrmw of Colorado, INC. | Aspen | CO | — | ◇ UNVERIFIED |
| IAIron Access, INC. | Houston | TX | — | ◇ UNVERIFIED |
| ICIron Crafters Security Products Inc | Ashland | MS | — | ◇ UNVERIFIED |
| IDIron Dog Fabrication INC | Santa Rosa | CA | — | ◇ UNVERIFIED |
| ILIronfab, LLC | Columbus | OH | — | ◇ UNVERIFIED |
| IFIron Fabrication Services, INC. | Jessup | MD | — | ◇ UNVERIFIED |
| IFIron Fence Specialists, INC. | Las Vegas | NV | — | ◇ UNVERIFIED |
| IIIronhead INC | Vale | OR | — | ◇ UNVERIFIED |
| IIIron Integrity LLC | Hayden | CO | — | ◇ UNVERIFIED |
