| Century Metal Spinning Co Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001, AS9100, ITAR | Bensenville, IL | MillingTurningLaserBendingWeldingFinishing | ISO 9001, AS9100, ITAR |
| Helander Metal Spinning Company LLC Milling, Turning, Laser, Waterjet, Welding, Stamping, EDM, Finishing · NADCAP | Lombard, IL | MillingTurningLaserWaterjetWeldingStampingEDMFinishing | NADCAP |
| Manufacture Design Innovation, Inc Milling, Turning, Welding | Gilberts, IL | MillingTurningWelding | - |
| Acme Industries, Inc Milling, Turning, Welding, Casting · ISO 9001, AS9100 | Elk Grove Village, IL | MillingTurningWeldingCasting | ISO 9001, AS9100 |
| CM Fabrication, LLC Milling, Laser, Welding, Finishing | Sycamore, IL | MillingLaserWeldingFinishing | - |
| Comet Fabricating & Welding Co Laser, Bending, Welding | Rockford, IL | LaserBendingWelding | - |
| Dupage Machine Products, Inc Welding, EDM | Bloomingdale, IL | WeldingEDM | - |
| Foster Works LLC Laser, Punching, Bending, Welding, Stamping, Finishing | Chicago, IL | LaserPunchingBendingWeldingStampingFinishing | - |
| Kadon Precision Machining Turning · ISO 9001 | Rockford, IL | Turning | ISO 9001 |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| M-1 Tool Works, Inc Milling, Turning, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Mchenry, IL | MillingTurningEDMGrindingFinishingAssembly | ISO 9001, AS9100 |
| Magnum Machining LLC Milling, Turning, Finishing | Richmond, IL | MillingTurningFinishing | - |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| Stuecklen Manufacturing Co Bending, Finishing | Franklin Park, IL | BendingFinishing | - |