| Wesco Machine & Tool Turning, Laser, Welding, Grinding | Shorewood, IL | TurningLaserWeldingGrinding | - |
| A.j.r. Industries, Inc Milling, Turning | Elk Grove Village, IL | MillingTurning | - |
| Ability Metal Company Milling, Turning, Assembly | Elk Grove Village, IL | MillingTurningAssembly | - |
| Accumation Swiss Turning, Swiss · ISO 9001 | Crystal Lake, IL | TurningSwiss | ISO 9001 |
| Ace of Diamonds International Inc Milling | Aurora, IL | Milling | - |
| American Machine Tools Co. Milling, Turning, Bending | Chicago, IL | MillingTurningBending | - |
| Anchor-Harvey Components LLC Milling, Forging, Finishing · ISO 9001, AS9100 | Freeport, IL | MillingForgingFinishing | ISO 9001, AS9100 |
| Art CNC Machining LLC Milling, Turning, Assembly · ISO 9001 | Bridgeview, IL | MillingTurningAssembly | ISO 9001 |
| 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 | - |
| Burns Machine Co Milling, Turning, Bending, Welding, Grinding, Assembly · ISO 9001 | Ottawa, IL | MillingTurningBendingWeldingGrindingAssembly | ISO 9001 |
| Calisota Parts, LLC Milling, Waterjet, Stamping, EDM | Frankfort, IL | MillingWaterjetStampingEDM | - |
| Camcraft Inc Milling, Turning, Grinding | Hanover Park, IL | MillingTurningGrinding | - |
| Center Tool Co Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Hampshire, IL | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Chicago CNC Machining Co. Milling, Turning, Bending, Welding | Hodgkins, IL | MillingTurningBendingWelding | - |
| Composite Cutter Technology Inc Grinding · ISO 9001, AS9100 | Wauconda, IL | Grinding | ISO 9001, AS9100 |
| Cornell Forge Company Welding, Forging, Finishing, Assembly · ISO 9001, AS9100, NADCAP | Chicago, IL | WeldingForgingFinishingAssembly | ISO 9001, AS9100, NADCAP |
| Deines-Nitz Solutions, LLC Milling, Finishing | Erie, IL | MillingFinishing | - |
| DJW Assembly Inc Milling, Turning | Arlington Heights, IL | MillingTurning | - |
| Dynomax Inc EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR | Wheeling, IL | EDMFinishingAssembly | ISO 9001, AS9100, ITAR |
| E. J. Basler Co Milling, Turning, Swiss, Grinding · ISO 9001 | Schiller Park, IL | MillingTurningSwissGrinding | ISO 9001 |
| Eclipse Precision Machining, LLC Milling, EDM · ISO 9001, AS9100 | Elk Grove Village, IL | MillingEDM | ISO 9001, AS9100 |
| EDM Intelligent Solutions Milling, EDM, Grinding · ISO 9001, ITAR | Bartlett, IL | MillingEDMGrinding | ISO 9001, ITAR |
| Emergent Manufacturing Solutions, LLC Milling, Turning · ISO 9001, AS9100, ITAR, ISO 13485, IATF 16949 | Loves Park, IL | MillingTurning | ISO 9001, AS9100, ITAR, ISO 13485, IATF 16949 |
| Evergreen Machining Services Milling, Welding, Stamping, Metal AM · ISO 9001 | Rockford, IL | MillingWeldingStampingMetal AM | ISO 9001 |
| Faspro Technologies, Inc Laser, Stamping, Assembly | Arlington Heights, IL | LaserStampingAssembly | - |
| Forge Resources Group Turning, Forging, Grinding, Finishing · ISO 9001, AS9100, ITAR | Dekalb, IL | TurningForgingGrindingFinishing | ISO 9001, AS9100, ITAR |
| Foster Works LLC Laser, Punching, Bending, Welding, Stamping, Finishing | Chicago, IL | LaserPunchingBendingWeldingStampingFinishing | - |
| G & Z Industries Inc Casting, EDM · ISO 9001, ITAR | Wheeling, IL | CastingEDM | ISO 9001, ITAR |
| General Machinery & Manufacturing Co Milling, Turning, Bending, Stamping · ISO 9001, AS9100 | Chicago, IL | MillingTurningBendingStamping | ISO 9001, AS9100 |
| Ifl Manufacturing Inc Milling, Stamping | Wauconda, IL | MillingStamping | - |
| Jacksonville Machine, Inc Milling, Turning, Welding, Grinding · ISO 9001 | Jacksonville, IL | MillingTurningWeldingGrinding | ISO 9001 |
| Kris Dee and Associates, Inc Milling, Casting · ISO 9001, AS9100, ITAR | South Elgin, IL | MillingCasting | ISO 9001, AS9100, ITAR |
| M-1 Tool Works, Inc Milling, Turning, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Mchenry, IL | MillingTurningEDMGrindingFinishingAssembly | ISO 9001, AS9100 |
| Magnum Steel Works Milling, Turning, Waterjet, Bending, Welding | Mount Vernon, IL | MillingTurningWaterjetBendingWelding | - |
| Mah Tooling Co Milling, Turning | Hickory Hills, IL | MillingTurning | - |
| Minic Precision, Inc Turning, Swiss · ISO 9001 | Spring Grove, IL | TurningSwiss | ISO 9001 |
| On Sh0re USA LLC Milling, Turning | Glendale Heights, IL | MillingTurning | - |
| Perfect 3D Solutions, LLC Assembly | St. Charles, IL | Assembly | - |
| Prismier, LLC Stamping, Casting · ISO 9001 | Bolingbrook, IL | StampingCasting | ISO 9001 |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| Saliba Industries Milling, Turning, Grinding | Waukegan, IL | MillingTurningGrinding | - |
| Sonic Manufacturing Corporation Milling, Welding, EDM, Grinding, Finishing, Assembly · AS9100, NADCAP | Elk Grove Village, IL | MillingWeldingEDMGrindingFinishingAssembly | AS9100, NADCAP |
| Stanley Spring and Stamping Corp Laser, Bending, Stamping, Assembly | Chicago, IL | LaserBendingStampingAssembly | - |
| Surface Finishes Welding, Grinding · ITAR | Addison, IL | WeldingGrinding | ITAR |
| Sycamore Precision, Inc Milling, Casting, Finishing | Genoa, IL | MillingCastingFinishing | - |
| Tech-Weld Inc Laser, Welding · NADCAP | Sycamore, IL | LaserWelding | NADCAP |
| The Bennu Group Inc Milling, Turning, Waterjet, Welding, Finishing · ISO 9001 | South Holland, IL | MillingTurningWaterjetWeldingFinishing | ISO 9001 |
| Thomason Machine Works Inc Milling, Turning, EDM · ISO 9001 | Rockford, IL | MillingTurningEDM | ISO 9001 |