| Aztec Plastic Company Welding, Stamping, Grinding, Finishing, Assembly | Chicago, IL | WeldingStampingGrindingFinishingAssembly | - |
| Camcraft Inc Milling, Turning, Grinding | Hanover Park, IL | MillingTurningGrinding | - |
| Chicago Metal Supply & Fabrication Inc Bending, Welding, Waterjet, Stamping | Chicago, IL | BendingWeldingWaterjetStamping | - |
| CM Fabrication, LLC Milling, Laser, Welding, Finishing | Sycamore, IL | MillingLaserWeldingFinishing | - |
| Composite Cutter Technology Inc Grinding · ISO 9001, AS9100 | Wauconda, IL | Grinding | ISO 9001, AS9100 |
| 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 |
| 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 | - |
| Forster Tool & Manufacturing Co Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, AS9100, ITAR, CMMC | Bensenville, IL | MillingTurningSwissGrindingFinishing | ISO 9001, AS9100, ITAR, CMMC |
| Frey & Weiss Precision Machining Inc Milling, Turning, Grinding, Assembly · ISO 9001 | Wood Dale, IL | MillingTurningGrindingAssembly | ISO 9001 |
| General Machinery & Manufacturing Co Milling, Turning, Bending, Stamping · ISO 9001, AS9100 | Chicago, IL | MillingTurningBendingStamping | ISO 9001, AS9100 |
| H3 Manufacturing Group LLC Laser, Bending, Welding, Finishing · ISO 9001 | Schaumburg, IL | LaserBendingWeldingFinishing | ISO 9001 |
| Hy-Tek Manufacturing Co., Inc Milling, Turning, Assembly · ISO 9001 | Sugar Grove, IL | MillingTurningAssembly | ISO 9001 |
| Jem Custom Products, Inc Milling, Finishing | Wauconda, IL | MillingFinishing | - |
| Kocsis Brothers Machine Company Welding, Assembly | Alsip, IL | WeldingAssembly | - |
| Krametech, Inc Milling, Finishing, Assembly | Lake Zurich, IL | MillingFinishingAssembly | - |
| Kris Dee and Associates, Inc Milling, Casting · ISO 9001, AS9100, ITAR | South Elgin, IL | MillingCasting | ISO 9001, AS9100, ITAR |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| LJ Fabricators, Inc. Bending, Laser, Welding · ISO 9001 | Rockford, IL | BendingLaserWelding | ISO 9001 |
| LZ Machine LLC Milling, Turning, Assembly | Eureka, IL | MillingTurningAssembly | - |
| M-1 Tool Works, Inc Milling, Turning, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Mchenry, IL | MillingTurningEDMGrindingFinishingAssembly | ISO 9001, AS9100 |
| Manufacture Design Innovation, Inc Milling, Turning, Welding | Gilberts, IL | MillingTurningWelding | - |
| Prototype & Production Co., Inc Milling, Turning, EDM, Grinding, Assembly · ISO 9001, ITAR | Wheeling, IL | MillingTurningEDMGrindingAssembly | ISO 9001, ITAR |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| Schmid Tool & Engineering Corp Milling, Turning, Swiss, Stamping, Grinding, Finishing, Assembly · ISO 9001, ITAR | Villa Park, IL | MillingTurningSwissStampingGrindingFinishingAssembly | ISO 9001, ITAR |
| Spyco Industries Inc Milling, Turning, Waterjet, Grinding · ISO 9001 | Burr Ridge, IL | MillingTurningWaterjetGrinding | ISO 9001 |
| Systems Powered Manufacturing, LLC Grinding, Finishing, Assembly | Saint Charles, IL | GrindingFinishingAssembly | - |
| Target Laser & Machining, Inc Laser, Bending, Welding · ISO 9001 | Rockford, IL | LaserBendingWelding | ISO 9001 |
| Walco Tool & Engineering Corp Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Romeoville, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| Waltz Brothers, Inc Turning, Grinding · ISO 9001 | Wheeling, IL | TurningGrinding | ISO 9001 |
| Alu-Bra Foundry, Inc Casting · ISO 9001 | Bensenville, IL | Casting | ISO 9001 |
| LD Redmer Milling, Turning, Swiss, Welding, Finishing · ISO 9001, ITAR, NADCAP | Bensenville, IL | MillingTurningSwissWeldingFinishing | ISO 9001, ITAR, NADCAP |
| Moritz Micro Company Milling, Waterjet, EDM, Grinding | Lisle, IL | MillingWaterjetEDMGrinding | - |
| Custom Laser Works LLC Laser, Bending, Welding | Addison, IL | LaserBendingWelding | - |
| Calisota Parts, LLC Milling, Waterjet, Stamping, EDM | Frankfort, IL | MillingWaterjetStampingEDM | - |
| Chicago Metal Fabricators Bending, Laser, Welding · ISO 9001, ITAR | Chicago, IL | BendingLaserWelding | ISO 9001, ITAR |
| Demco Products Milling, Turning, Swiss, Finishing, Assembly · ISO 9001 | Oak Lawn, IL | MillingTurningSwissFinishingAssembly | ISO 9001 |
| E. J. Basler Co Milling, Turning, Swiss, Grinding · ISO 9001 | Schiller Park, IL | MillingTurningSwissGrinding | ISO 9001 |
| 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 | - |
| Prismier, LLC Stamping, Casting · ISO 9001 | Bolingbrook, IL | StampingCasting | ISO 9001 |
| PW Jet Laser, Waterjet, Bending, Welding, Stamping, Finishing · ISO 9001 | Crystal Lake, IL | LaserWaterjetBendingWeldingStampingFinishing | ISO 9001 |
| Taylor EDM Specialties LLC Milling, EDM, Grinding | Wauconda, IL | MillingEDMGrinding | - |
| Toolex Corp Milling, Welding, EDM, Grinding, Finishing | Addison, IL | MillingWeldingEDMGrindingFinishing | - |
| Wpa Works LLC Milling, Turning, Swiss, EDM, Finishing · ISO 9001 | Elgin, IL | MillingTurningSwissEDMFinishing | ISO 9001 |