| Ifl Manufacturing Inc Milling, Stamping | Wauconda, IL | MillingStamping | - |
| J. T. Cullen Co Inc Milling | Fulton, IL | Milling | - |
| Kocsis Brothers Machine Company Welding, Assembly | Alsip, IL | WeldingAssembly | - |
| Krametech, Inc Milling, Finishing, Assembly | Lake Zurich, IL | MillingFinishingAssembly | - |
| Kris Dee and Associates, Inc Milling, Casting · ISO 9001, AS9100, ITAR | South Elgin, IL | MillingCasting | ISO 9001, AS9100, ITAR |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| LD Redmer Milling, Turning, Swiss, Welding, Finishing · ISO 9001, ITAR, NADCAP | Bensenville, IL | MillingTurningSwissWeldingFinishing | ISO 9001, ITAR, NADCAP |
| LJ Fabricators, Inc. Bending, Laser, Welding · ISO 9001 | Rockford, IL | BendingLaserWelding | ISO 9001 |
| Magnum Machining LLC Milling, Turning, Finishing | Richmond, IL | MillingTurningFinishing | - |
| Mah Tooling Co Milling, Turning | Hickory Hills, IL | MillingTurning | - |
| Minic Precision, Inc Turning, Swiss · ISO 9001 | Spring Grove, IL | TurningSwiss | ISO 9001 |
| NKP Metals LLC Waterjet, Welding | Chicago, IL | WaterjetWelding | - |
| On Sh0re USA LLC Milling, Turning | Glendale Heights, IL | MillingTurning | - |
| Perfect 3D Solutions, LLC Assembly | St. Charles, IL | Assembly | - |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| Sanks Machining Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Staunton, IL | MillingTurningWaterjetWeldingEDMGrinding | - |
| Schmid Tool & Engineering Corp Milling, Turning, Swiss, Stamping, Grinding, Finishing, Assembly · ISO 9001, ITAR | Villa Park, IL | MillingTurningSwissStampingGrindingFinishingAssembly | ISO 9001, ITAR |
| Slagel Manufacturing, Inc Bending, Welding, Finishing · ISO 9001 | Forrest, IL | BendingWeldingFinishing | ISO 9001 |
| Sonic Manufacturing Corporation Milling, Welding, EDM, Grinding, Finishing, Assembly · AS9100, NADCAP | Elk Grove Village, IL | MillingWeldingEDMGrindingFinishingAssembly | AS9100, NADCAP |
| Stuecklen Manufacturing Co Bending, Finishing | Franklin Park, IL | BendingFinishing | - |
| Systems Powered Manufacturing, LLC Grinding, Finishing, Assembly | Saint Charles, IL | GrindingFinishingAssembly | - |
| The Bennu Group Inc Milling, Turning, Waterjet, Welding, Finishing · ISO 9001 | South Holland, IL | MillingTurningWaterjetWeldingFinishing | ISO 9001 |
| Wesco Machine & Tool Turning, Laser, Welding, Grinding | Shorewood, IL | TurningLaserWeldingGrinding | - |