| Spyco Industries Inc Milling, Turning, Waterjet, Grinding · ISO 9001 | Burr Ridge, IL | MillingTurningWaterjetGrinding | ISO 9001 |
| Stanley Machining & Tool Corp Milling, Turning · ISO 9001 | Carpentersville, IL | MillingTurning | ISO 9001 |
| Thomason Machine Works Inc Milling, Turning, EDM · ISO 9001 | Rockford, IL | MillingTurningEDM | ISO 9001 |
| Waltz Brothers, Inc Turning, Grinding · ISO 9001 | Wheeling, IL | TurningGrinding | ISO 9001 |
| On Sh0re USA LLC Milling, Turning | Glendale Heights, IL | MillingTurning | - |
| R & W Machine & Tool Works Milling, Turning · ISO 9001 | Chicago, IL | MillingTurning | ISO 9001 |
| Aztec Plastic Company Welding, Stamping, Grinding, Finishing, Assembly | Chicago, IL | WeldingStampingGrindingFinishingAssembly | - |
| CM Fabrication, LLC Milling, Laser, Welding, Finishing | Sycamore, IL | MillingLaserWeldingFinishing | - |
| Deines-Nitz Solutions, LLC Milling, Finishing | Erie, IL | MillingFinishing | - |
| Eclipse Precision Machining, LLC Milling, EDM · ISO 9001, AS9100 | Elk Grove Village, IL | MillingEDM | ISO 9001, AS9100 |
| Ella Engineering Incorporated Milling, Turning, Finishing | Elk Grove Village, IL | MillingTurningFinishing | - |
| Foster Works LLC Laser, Punching, Bending, Welding, Stamping, Finishing | Chicago, IL | LaserPunchingBendingWeldingStampingFinishing | - |
| Helander Metal Spinning Company LLC Milling, Turning, Laser, Waterjet, Welding, Stamping, EDM, Finishing · NADCAP | Lombard, IL | MillingTurningLaserWaterjetWeldingStampingEDMFinishing | NADCAP |
| Jem Custom Products, Inc Milling, Finishing | Wauconda, IL | MillingFinishing | - |
| Panek Precision Products LLC Milling, Turning, Stamping, Grinding, Finishing, Assembly · ITAR | Northbrook, IL | MillingTurningStampingGrindingFinishingAssembly | ITAR |
| Quadrant Tool and Manufacturing Company Milling, Turning, EDM, Grinding, Finishing | Schaumburg, IL | MillingTurningEDMGrindingFinishing | - |
| Quality Metal Products Inc Milling, Turning, Finishing | Peoria, IL | MillingTurningFinishing | - |
| Saporito Finishing Co Welding, Finishing · NADCAP | Cicero, IL | WeldingFinishing | NADCAP |
| Sonic Manufacturing Corporation Milling, Welding, EDM, Grinding, Finishing, Assembly · AS9100, NADCAP | Elk Grove Village, IL | MillingWeldingEDMGrindingFinishingAssembly | AS9100, NADCAP |
| Stuecklen Manufacturing Co Bending, Finishing | Franklin Park, IL | BendingFinishing | - |
| Sycamore Precision, Inc Milling, Casting, Finishing | Genoa, IL | MillingCastingFinishing | - |
| Systems Powered Manufacturing, LLC Grinding, Finishing, Assembly | Saint Charles, IL | GrindingFinishingAssembly | - |
| Titan Metal Fabricators, Inc Welding, Finishing | Northbrook, IL | WeldingFinishing | - |
| Toolex Corp Milling, Welding, EDM, Grinding, Finishing | Addison, IL | MillingWeldingEDMGrindingFinishing | - |
| Wozniak Industries Inc Welding, Stamping, Forging | Schaumburg, IL | WeldingStampingForging | - |
| 360 Machine Shop Milling, Turning, Laser, Welding, Metal AM | Bloomington, IL | MillingTurningLaserWeldingMetal AM | - |
| Abbate Screw Products Inc Milling, Swiss, Grinding | Roselle, IL | MillingSwissGrinding | - |
| Ability Metal Company Milling, Turning, Assembly | Elk Grove Village, IL | MillingTurningAssembly | - |
| American Machine Tools Co. Milling, Turning, Bending | Chicago, IL | MillingTurningBending | - |
| Astoria Wire Products Inc Milling, Laser, Punching, Bending, Welding | Bedford Park, IL | MillingLaserPunchingBendingWelding | - |
| Atlas Tool & Die Works Inc Turning, Laser, Waterjet, Welding, Stamping, EDM, Assembly | Lyons, IL | TurningLaserWaterjetWeldingStampingEDMAssembly | - |
| Avanti Engineering Inc Milling, Turning, Swiss, EDM, Grinding, Finishing, Assembly · ISO 9001 | Glendale Heights, IL | MillingTurningSwissEDMGrindingFinishingAssembly | ISO 9001 |
| Awerkamp Machine Co Welding | Quincy, IL | Welding | - |
| Bland Brothers Enterprises Milling, Welding, Assembly | Springfield, IL | MillingWeldingAssembly | - |
| Calisota Parts, LLC Milling, Waterjet, Stamping, EDM | Frankfort, IL | MillingWaterjetStampingEDM | - |
| 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 | - |
| Dupage Machine Products, Inc Welding, EDM | Bloomingdale, IL | WeldingEDM | - |
| Faspro Technologies, Inc Laser, Stamping, Assembly | Arlington Heights, IL | LaserStampingAssembly | - |
| J. T. Cullen Co Inc Milling | Fulton, IL | Milling | - |
| Ki Machine Tools & Productions Inc Milling, Turning, Bending, Welding, EDM, Grinding | Loves Park, IL | MillingTurningBendingWeldingEDMGrinding | - |
| Kocsis Brothers Machine Company Welding, Assembly | Alsip, IL | WeldingAssembly | - |
| La Frenz Pattern Company, Incorporated Milling, Welding | Moline, IL | MillingWelding | - |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| LD Redmer Milling, Turning, Swiss, Welding, Finishing · ISO 9001, ITAR, NADCAP | Bensenville, IL | MillingTurningSwissWeldingFinishing | ISO 9001, ITAR, NADCAP |
| Magnum Steel Works Milling, Turning, Waterjet, Bending, Welding | Mount Vernon, IL | MillingTurningWaterjetBendingWelding | - |