| Chicago Fabrications Turning, Bending, Welding | Chicago, IL | TurningBendingWelding | - |
| Comet Fabricating & Welding Co Laser, Bending, Welding | Rockford, IL | LaserBendingWelding | - |
| Ki Machine Tools & Productions Inc Milling, Turning, Bending, Welding, EDM, Grinding | Loves Park, IL | MillingTurningBendingWeldingEDMGrinding | - |
| Mennie's Machine Co Milling, Turning, Welding, Grinding · IATF 16949 | Mark, IL | MillingTurningWeldingGrinding | IATF 16949 |
| On Sh0re USA LLC Milling, Turning | Glendale Heights, IL | MillingTurning | - |
| Quadrant Tool and Manufacturing Company Milling, Turning, EDM, Grinding, Finishing | Schaumburg, IL | MillingTurningEDMGrindingFinishing | - |
| Titan Metal Fabricators, Inc Welding, Finishing | Northbrook, IL | WeldingFinishing | - |
| Center Tool Co Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Hampshire, IL | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Dupage Machine Products, Inc Welding, EDM | Bloomingdale, IL | WeldingEDM | - |
| LD Redmer Milling, Turning, Swiss, Welding, Finishing · ISO 9001, ITAR, NADCAP | Bensenville, IL | MillingTurningSwissWeldingFinishing | ISO 9001, ITAR, NADCAP |
| Manufacture Design Innovation, Inc Milling, Turning, Welding | Gilberts, IL | MillingTurningWelding | - |
| PW Jet Laser, Waterjet, Bending, Welding, Stamping, Finishing · ISO 9001 | Crystal Lake, IL | LaserWaterjetBendingWeldingStampingFinishing | ISO 9001 |
| R & W Machine & Tool Works Milling, Turning · ISO 9001 | Chicago, IL | MillingTurning | ISO 9001 |
| Taylor EDM Specialties LLC Milling, EDM, Grinding | Wauconda, IL | MillingEDMGrinding | - |
| Walco Tool & Engineering Corp Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Romeoville, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| Wrightwood Precision Products Company Milling, Turning | Chicago, IL | MillingTurning | - |
| 425 Manufacturing Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| Ace of Diamonds International Inc Milling | Aurora, IL | Milling | - |
| American Machining Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Ottawa, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| Art CNC Machining LLC Milling, Turning, Assembly · ISO 9001 | Bridgeview, IL | MillingTurningAssembly | ISO 9001 |
| Avanti Engineering Inc Milling, Turning, Swiss, EDM, Grinding, Finishing, Assembly · ISO 9001 | Glendale Heights, IL | MillingTurningSwissEDMGrindingFinishingAssembly | ISO 9001 |
| Bem CNC Milling, Turning | Schaumburg, IL | MillingTurning | - |
| Dynomax Inc EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR | Wheeling, IL | EDMFinishingAssembly | ISO 9001, AS9100, ITAR |
| G & M Manufacturing Corp Milling, Waterjet, Stamping, EDM, Finishing · ISO 9001 | Crystal Lake, IL | MillingWaterjetStampingEDMFinishing | ISO 9001 |
| Prototype & Production Co., Inc Milling, Turning, EDM, Grinding, Assembly · ISO 9001, ITAR | Wheeling, IL | MillingTurningEDMGrindingAssembly | ISO 9001, ITAR |
| Alu-Bra Foundry, Inc Casting · ISO 9001 | Bensenville, IL | Casting | ISO 9001 |
| Crown Machine Inc Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| DJW Assembly Inc Milling, Turning | Arlington Heights, IL | MillingTurning | - |
| General Machinery & Manufacturing Co Milling, Turning, Bending, Stamping · ISO 9001, AS9100 | Chicago, IL | MillingTurningBendingStamping | ISO 9001, AS9100 |
| Chicago CNC Machining Co. Milling, Turning, Bending, Welding | Hodgkins, IL | MillingTurningBendingWelding | - |
| General Machine Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Grinding, Finishing | Chicago, IL | MillingTurningLaserWaterjetPunchingBendingWeldingGrindingFinishing | - |
| Hennig Milling · ISO 9001, AS9100 | Rockford, IL | Milling | ISO 9001, AS9100 |
| Toolex Corp Milling, Welding, EDM, Grinding, Finishing | Addison, IL | MillingWeldingEDMGrindingFinishing | - |
| Awerkamp Machine Co Welding | Quincy, IL | Welding | - |
| Ifl Manufacturing Inc Milling, Stamping | Wauconda, IL | MillingStamping | - |
| Krametech, Inc Milling, Finishing, Assembly | Lake Zurich, IL | MillingFinishingAssembly | - |
| La Frenz Pattern Company, Incorporated Milling, Welding | Moline, IL | MillingWelding | - |
| Magnum Machining LLC Milling, Turning, Finishing | Richmond, IL | MillingTurningFinishing | - |
| Meyer Tool & Manufacturing, Inc Milling, Turning, Welding · ITAR | Oak Lawn, IL | MillingTurningWelding | ITAR |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| Camcraft Inc Milling, Turning, Grinding | Hanover Park, IL | MillingTurningGrinding | - |
| LZ Machine LLC Milling, Turning, Assembly | Eureka, IL | MillingTurningAssembly | - |
| Wagner Machine Company Milling, Turning, Swiss, Waterjet, Metal AM, EDM | Champaign, IL | MillingTurningSwissWaterjetMetal AMEDM | - |
| J. T. Cullen Co Inc Milling | Fulton, IL | Milling | - |
| Mah Tooling Co Milling, Turning | Hickory Hills, IL | MillingTurning | - |