| Mah Tooling Co Milling, Turning | Hickory Hills, IL | MillingTurning | - |
| Manufacture Design Innovation, Inc Milling, Turning, Welding | Gilberts, IL | MillingTurningWelding | - |
| Mennie's Machine Co Milling, Turning, Welding, Grinding · IATF 16949 | Mark, IL | MillingTurningWeldingGrinding | IATF 16949 |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| Perfect 3D Solutions, LLC Assembly | St. Charles, IL | Assembly | - |
| PW Jet Laser, Waterjet, Bending, Welding, Stamping, Finishing · ISO 9001 | Crystal Lake, IL | LaserWaterjetBendingWeldingStampingFinishing | ISO 9001 |
| Slagel Manufacturing, Inc Bending, Welding, Finishing · ISO 9001 | Forrest, IL | BendingWeldingFinishing | ISO 9001 |
| Smith & Richardson Manufacturing Co Milling, Stamping, Casting | Geneva, IL | MillingStampingCasting | - |
| Stanley Spring and Stamping Corp Laser, Bending, Stamping, Assembly | Chicago, IL | LaserBendingStampingAssembly | - |
| Taylor EDM Specialties LLC Milling, EDM, Grinding | Wauconda, IL | MillingEDMGrinding | - |
| United Standard Industries Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100 | Glenview, IL | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100 |
| Wagner Machine Company Milling, Turning, Swiss, Waterjet, Metal AM, EDM | Champaign, IL | MillingTurningSwissWaterjetMetal AMEDM | - |
| Wesco Machine & Tool Turning, Laser, Welding, Grinding | Shorewood, IL | TurningLaserWeldingGrinding | - |
| Wrightwood Precision Products Company Milling, Turning | Chicago, IL | MillingTurning | - |
| X Cel Technologies Inc Milling, Assembly | Tinley Park, IL | MillingAssembly | - |
| 425 Manufacturing Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| Acme Industries, Inc Milling, Turning, Welding, Casting · ISO 9001, AS9100 | Elk Grove Village, IL | MillingTurningWeldingCasting | ISO 9001, AS9100 |
| Art CNC Machining LLC Milling, Turning, Assembly · ISO 9001 | Bridgeview, IL | MillingTurningAssembly | ISO 9001 |
| Chicago Fabrications Turning, Bending, Welding | Chicago, IL | TurningBendingWelding | - |
| Evergreen Machining Services Milling, Welding, Stamping, Metal AM · ISO 9001 | Rockford, IL | MillingWeldingStampingMetal AM | ISO 9001 |
| G & Z Industries Inc Casting, EDM · ISO 9001, ITAR | Wheeling, IL | CastingEDM | ISO 9001, ITAR |
| Hennig Milling · ISO 9001, AS9100 | Rockford, IL | Milling | ISO 9001, AS9100 |
| Moritz Micro Company Milling, Waterjet, EDM, Grinding | Lisle, IL | MillingWaterjetEDMGrinding | - |
| Pegasus Mfg Inc Milling, Turning, Metal AM · ISO 9001, AS9100 | Galesburg, IL | MillingTurningMetal AM | ISO 9001, AS9100 |
| Prismier, LLC Stamping, Casting · ISO 9001 | Bolingbrook, IL | StampingCasting | ISO 9001 |
| Target Laser & Machining, Inc Laser, Bending, Welding · ISO 9001 | Rockford, IL | LaserBendingWelding | ISO 9001 |
| Ace of Diamonds International Inc Milling | Aurora, IL | Milling | - |
| Custom Laser Works LLC Laser, Bending, Welding | Addison, IL | LaserBendingWelding | - |
| General Machine Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Grinding, Finishing | Chicago, IL | MillingTurningLaserWaterjetPunchingBendingWeldingGrindingFinishing | - |
| Krametech, Inc Milling, Finishing, Assembly | Lake Zurich, IL | MillingFinishingAssembly | - |
| Magnum Machining LLC Milling, Turning, Finishing | Richmond, IL | MillingTurningFinishing | - |
| R C Industries Inc Finishing | Chicago, IL | Finishing | - |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| Sugar River Machine Inc Milling, Turning, Welding, Grinding, Finishing, Assembly | South Beloit, IL | MillingTurningWeldingGrindingFinishingAssembly | - |
| A.j.r. Industries, Inc Milling, Turning | Elk Grove Village, IL | MillingTurning | - |
| B T M Industries Inc Milling, Turning, Welding, Casting, Grinding | Woodstock, IL | MillingTurningWeldingCastingGrinding | - |
| Bem CNC Milling, Turning | Schaumburg, IL | MillingTurning | - |
| Camcraft Inc Milling, Turning, Grinding | Hanover Park, IL | MillingTurningGrinding | - |
| DJW Assembly Inc Milling, Turning | Arlington Heights, IL | MillingTurning | - |
| Ifl Manufacturing Inc Milling, Stamping | Wauconda, IL | MillingStamping | - |
| LZ Machine LLC Milling, Turning, Assembly | Eureka, IL | MillingTurningAssembly | - |
| NKP Metals LLC Waterjet, Welding | Chicago, IL | WaterjetWelding | - |
| Saliba Industries Milling, Turning, Grinding | Waukegan, IL | MillingTurningGrinding | - |
| Sanks Machining Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Staunton, IL | MillingTurningWaterjetWeldingEDMGrinding | - |
| Surface Finishes Welding, Grinding · ITAR | Addison, IL | WeldingGrinding | ITAR |
| Tech-Weld Inc Laser, Welding · NADCAP | Sycamore, IL | LaserWelding | NADCAP |