| Astoria Wire Products Inc Milling, Laser, Punching, Bending, Welding | Bedford Park, IL | MillingLaserPunchingBendingWelding | - |
| Awerkamp Machine Co Welding | Quincy, IL | Welding | - |
| Bem CNC Milling, Turning | Schaumburg, IL | MillingTurning | - |
| Camcraft Inc Milling, Turning, Grinding | Hanover Park, IL | MillingTurningGrinding | - |
| Cast Technologies Inc Casting | Peoria, IL | Casting | - |
| Chicago CNC Machining Co. Milling, Turning, Bending, Welding | Hodgkins, IL | MillingTurningBendingWelding | - |
| Chicago Magnesium Casting Co Welding, Casting · AS9100, NADCAP | Blue Island, IL | WeldingCasting | AS9100, NADCAP |
| Chicago Metal Supply & Fabrication Inc Bending, Welding, Waterjet, Stamping | Chicago, IL | BendingWeldingWaterjetStamping | - |
| Clinkenbeard & Associates Inc Milling, Casting, Assembly · AS9100, ITAR | South Beloit, IL | MillingCastingAssembly | AS9100, ITAR |
| Comet Fabricating & Welding Co Laser, Bending, Welding | Rockford, IL | LaserBendingWelding | - |
| Custom Laser Works LLC Laser, Bending, Welding | Addison, IL | LaserBendingWelding | - |
| Deines-Nitz Solutions, LLC Milling, Finishing | Erie, IL | MillingFinishing | - |
| DJW Assembly Inc Milling, Turning | Arlington Heights, IL | MillingTurning | - |
| Dupage Machine Products, Inc Welding, EDM | Bloomingdale, IL | WeldingEDM | - |
| Faspro Technologies, Inc Laser, Stamping, Assembly | Arlington Heights, IL | LaserStampingAssembly | - |
| Ifl Manufacturing Inc Milling, Stamping | Wauconda, IL | MillingStamping | - |
| J. T. Cullen Co Inc Milling | Fulton, IL | Milling | - |
| Jem Custom Products, Inc Milling, Finishing | Wauconda, IL | MillingFinishing | - |
| Ki Machine Tools & Productions Inc Milling, Turning, Bending, Welding, EDM, Grinding | Loves Park, IL | MillingTurningBendingWeldingEDMGrinding | - |
| La Frenz Pattern Company, Incorporated Milling, Welding | Moline, IL | MillingWelding | - |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| LZ Machine LLC Milling, Turning, Assembly | Eureka, IL | MillingTurningAssembly | - |
| 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 |
| Meyer Tool & Manufacturing, Inc Milling, Turning, Welding · ITAR | Oak Lawn, IL | MillingTurningWelding | ITAR |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| On Sh0re USA LLC Milling, Turning | Glendale Heights, IL | MillingTurning | - |
| Perfect 3D Solutions, LLC Assembly | St. Charles, IL | Assembly | - |
| Saliba Industries Milling, Turning, Grinding | Waukegan, IL | MillingTurningGrinding | - |
| Sanks Machining Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Staunton, IL | MillingTurningWaterjetWeldingEDMGrinding | - |
| Smith & Richardson Manufacturing Co Milling, Stamping, Casting | Geneva, IL | MillingStampingCasting | - |
| Stanley Spring and Stamping Corp Laser, Bending, Stamping, Assembly | Chicago, IL | LaserBendingStampingAssembly | - |
| Systems Powered Manufacturing, LLC Grinding, Finishing, Assembly | Saint Charles, IL | GrindingFinishingAssembly | - |
| Taylor EDM Specialties LLC Milling, EDM, Grinding | Wauconda, IL | MillingEDMGrinding | - |
| Tech-Weld Inc Laser, Welding · NADCAP | Sycamore, IL | LaserWelding | NADCAP |
| Wesco Machine & Tool Turning, Laser, Welding, Grinding | Shorewood, IL | TurningLaserWeldingGrinding | - |
| X Cel Technologies Inc Milling, Assembly | Tinley Park, IL | MillingAssembly | - |