| Panek Precision Products LLC Milling, Turning, Stamping, Grinding, Finishing, Assembly · ITAR | Northbrook, IL | MillingTurningStampingGrindingFinishingAssembly | ITAR |
| Helander Metal Spinning Company LLC Milling, Turning, Laser, Waterjet, Welding, Stamping, EDM, Finishing · NADCAP | Lombard, IL | MillingTurningLaserWaterjetWeldingStampingEDMFinishing | NADCAP |
| Kaskaskia Tool and Machine, Inc Milling, Turning, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | New Athens, IL | MillingTurningBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| 360 Machine Shop Milling, Turning, Laser, Welding, Metal AM | Bloomington, IL | MillingTurningLaserWeldingMetal AM | - |
| A.j.r. Industries, Inc Milling, Turning | Elk Grove Village, IL | MillingTurning | - |
| Accumation Swiss Turning, Swiss · ISO 9001 | Crystal Lake, IL | TurningSwiss | ISO 9001 |
| Acme Industries, Inc Milling, Turning, Welding, Casting · ISO 9001, AS9100 | Elk Grove Village, IL | MillingTurningWeldingCasting | ISO 9001, AS9100 |
| Alanson Mfg L.L.C Turning, Finishing · ISO 9001, ITAR | Chicago, IL | TurningFinishing | ISO 9001, ITAR |
| American Machine Tools Co. Milling, Turning, Bending | Chicago, IL | MillingTurningBending | - |
| 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 |
| B T M Industries Inc Milling, Turning, Welding, Casting, Grinding | Woodstock, IL | MillingTurningWeldingCastingGrinding | - |
| Bem CNC Milling, Turning | Schaumburg, IL | MillingTurning | - |
| Bennett Metal Products Inc Milling, Turning, Waterjet, Welding · ISO 9001, ITAR | Mount Vernon, IL | MillingTurningWaterjetWelding | ISO 9001, ITAR |
| Betts Precision, Inc Milling, Turning, EDM, Grinding · AS9100, ISO 13485 | Alsip, IL | MillingTurningEDMGrinding | AS9100, ISO 13485 |
| Burns Machine Co Milling, Turning, Bending, Welding, Grinding, Assembly · ISO 9001 | Ottawa, IL | MillingTurningBendingWeldingGrindingAssembly | ISO 9001 |
| Center Tool Co Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Hampshire, IL | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Century Metal Spinning Co Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001, AS9100, ITAR | Bensenville, IL | MillingTurningLaserBendingWeldingFinishing | ISO 9001, AS9100, ITAR |
| Chicago CNC Machining Co. Milling, Turning, Bending, Welding | Hodgkins, IL | MillingTurningBendingWelding | - |
| Crown Machine Inc Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| DJW Assembly Inc Milling, Turning | Arlington Heights, IL | MillingTurning | - |
| Ella Engineering Incorporated Milling, Turning, Finishing | Elk Grove Village, IL | MillingTurningFinishing | - |
| 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 |
| Eton Machine Company Limited Milling, Turning, Swiss, Grinding, Assembly · ISO 9001 | Elgin, IL | MillingTurningSwissGrindingAssembly | ISO 9001 |
| General Machine Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Grinding, Finishing | Chicago, IL | MillingTurningLaserWaterjetPunchingBendingWeldingGrindingFinishing | - |
| Jacksonville Machine, Inc Milling, Turning, Welding, Grinding · ISO 9001 | Jacksonville, IL | MillingTurningWeldingGrinding | ISO 9001 |
| Kadon Precision Machining Turning · ISO 9001 | Rockford, IL | Turning | ISO 9001 |
| Ki Machine Tools & Productions Inc Milling, Turning, Bending, Welding, EDM, Grinding | Loves Park, IL | MillingTurningBendingWeldingEDMGrinding | - |
| Machining Systems Corporation Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Crestwood, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| Magnum Machining LLC Milling, Turning, Finishing | Richmond, IL | MillingTurningFinishing | - |
| Magnum Steel Works Milling, Turning, Waterjet, Bending, Welding | Mount Vernon, IL | MillingTurningWaterjetBendingWelding | - |
| Mah Tooling Co Milling, Turning | Hickory Hills, IL | MillingTurning | - |
| 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 |
| Minic Precision, Inc Turning, Swiss · ISO 9001 | Spring Grove, IL | TurningSwiss | ISO 9001 |
| Morgan Bronze Products, Inc Turning, Welding, Casting · ISO 9001 | Lake Zurich, IL | TurningWeldingCasting | ISO 9001 |
| Murphy Machine Products, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001 | Wood Dale, IL | MillingTurningSwissGrindingFinishing | ISO 9001 |
| On Sh0re USA LLC Milling, Turning | Glendale Heights, IL | MillingTurning | - |
| Pegasus Mfg Inc Milling, Turning, Metal AM · ISO 9001, AS9100 | Galesburg, IL | MillingTurningMetal AM | ISO 9001, AS9100 |
| Quadrant Tool and Manufacturing Company Milling, Turning, EDM, Grinding, Finishing | Schaumburg, IL | MillingTurningEDMGrindingFinishing | - |
| Quality Metal Products Inc Milling, Turning, Finishing | Peoria, IL | MillingTurningFinishing | - |
| Saliba Industries Milling, Turning, Grinding | Waukegan, IL | MillingTurningGrinding | - |
| Sanks Machining Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Staunton, IL | MillingTurningWaterjetWeldingEDMGrinding | - |
| Stanley Machining & Tool Corp Milling, Turning · ISO 9001 | Carpentersville, IL | MillingTurning | ISO 9001 |
| Sugar River Machine Inc Milling, Turning, Welding, Grinding, Finishing, Assembly | South Beloit, IL | MillingTurningWeldingGrindingFinishingAssembly | - |
| Swiss Automation, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, ITAR, ISO 13485 | Barrington, IL | MillingTurningSwissGrindingFinishing | ISO 9001, ITAR, ISO 13485 |
| 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 |
| United Standard Industries Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100 | Glenview, IL | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100 |