| Waltz Brothers, Inc Turning, Grinding · ISO 9001 | Wheeling, IL | TurningGrinding | ISO 9001 |
| Frey & Weiss Precision Machining Inc Milling, Turning, Grinding, Assembly · ISO 9001 | Wood Dale, IL | MillingTurningGrindingAssembly | ISO 9001 |
| Wagner Machine Company Milling, Turning, Swiss, Waterjet, Metal AM, EDM | Champaign, IL | MillingTurningSwissWaterjetMetal AMEDM | - |
| Walco Tool & Engineering Corp Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Romeoville, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| Wozniak Industries Inc Welding, Stamping, Forging | Schaumburg, IL | WeldingStampingForging | - |
| Wpa Works LLC Milling, Turning, Swiss, EDM, Finishing · ISO 9001 | Elgin, IL | MillingTurningSwissEDMFinishing | ISO 9001 |
| Wesco Machine & Tool Turning, Laser, Welding, Grinding | Shorewood, IL | TurningLaserWeldingGrinding | - |
| Abbate Screw Products Inc Milling, Swiss, Grinding | Roselle, IL | MillingSwissGrinding | - |
| Astoria Wire Products Inc Milling, Laser, Punching, Bending, Welding | Bedford Park, IL | MillingLaserPunchingBendingWelding | - |
| Awerkamp Machine Co Welding | Quincy, IL | Welding | - |
| Crown Machine Inc Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| Foster Works LLC Laser, Punching, Bending, Welding, Stamping, Finishing | Chicago, IL | LaserPunchingBendingWeldingStampingFinishing | - |
| 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 | - |
| PW Jet Laser, Waterjet, Bending, Welding, Stamping, Finishing · ISO 9001 | Crystal Lake, IL | LaserWaterjetBendingWeldingStampingFinishing | ISO 9001 |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| Swiss Automation, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, ITAR, ISO 13485 | Barrington, IL | MillingTurningSwissGrindingFinishing | ISO 9001, ITAR, ISO 13485 |
| Systems Powered Manufacturing, LLC Grinding, Finishing, Assembly | Saint Charles, IL | GrindingFinishingAssembly | - |
| Tech-Weld Inc Laser, Welding · NADCAP | Sycamore, IL | LaserWelding | NADCAP |
| Wrightwood Precision Products Company Milling, Turning | Chicago, IL | MillingTurning | - |
| B T M Industries Inc Milling, Turning, Welding, Casting, Grinding | Woodstock, IL | MillingTurningWeldingCastingGrinding | - |
| 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 |
| Jem Custom Products, Inc Milling, Finishing | Wauconda, IL | MillingFinishing | - |
| Murphy Machine Products, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001 | Wood Dale, IL | MillingTurningSwissGrindingFinishing | ISO 9001 |
| Accumation Swiss Turning, Swiss · ISO 9001 | Crystal Lake, IL | TurningSwiss | ISO 9001 |
| Atlas Tool & Die Works Inc Turning, Laser, Waterjet, Welding, Stamping, EDM, Assembly | Lyons, IL | TurningLaserWaterjetWeldingStampingEDMAssembly | - |
| Comet Fabricating & Welding Co Laser, Bending, Welding | Rockford, IL | LaserBendingWelding | - |
| Composite Cutter Technology Inc Grinding · ISO 9001, AS9100 | Wauconda, IL | Grinding | ISO 9001, AS9100 |
| Custom Laser Works LLC Laser, Bending, Welding | Addison, IL | LaserBendingWelding | - |
| G & Z Industries Inc Casting, EDM · ISO 9001, ITAR | Wheeling, IL | CastingEDM | ISO 9001, ITAR |
| Ifl Manufacturing Inc Milling, Stamping | Wauconda, IL | MillingStamping | - |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| Prototype & Production Co., Inc Milling, Turning, EDM, Grinding, Assembly · ISO 9001, ITAR | Wheeling, IL | MillingTurningEDMGrindingAssembly | ISO 9001, ITAR |
| R & W Machine & Tool Works Milling, Turning · ISO 9001 | Chicago, IL | MillingTurning | ISO 9001 |
| Saliba Industries Milling, Turning, Grinding | Waukegan, IL | MillingTurningGrinding | - |
| Taylor EDM Specialties LLC Milling, EDM, Grinding | Wauconda, IL | MillingEDMGrinding | - |
| Thomason Machine Works Inc Milling, Turning, EDM · ISO 9001 | Rockford, IL | MillingTurningEDM | ISO 9001 |
| NKP Metals LLC Waterjet, Welding | Chicago, IL | WaterjetWelding | - |
| Hennig Milling · ISO 9001, AS9100 | Rockford, IL | Milling | ISO 9001, AS9100 |
| 360 Machine Shop Milling, Turning, Laser, Welding, Metal AM | Bloomington, IL | MillingTurningLaserWeldingMetal AM | - |
| 425 Manufacturing Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| Accurate Metals Illinois Laser, Welding · ISO 9001 | Rockford, IL | LaserWelding | ISO 9001 |
| Acme Industries, Inc Milling, Turning, Welding, Casting · ISO 9001, AS9100 | Elk Grove Village, IL | MillingTurningWeldingCasting | ISO 9001, AS9100 |
| American Machining Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Ottawa, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| Anchor-Harvey Components LLC Milling, Forging, Finishing · ISO 9001, AS9100 | Freeport, IL | MillingForgingFinishing | ISO 9001, AS9100 |
| Avanti Engineering Inc Milling, Turning, Swiss, EDM, Grinding, Finishing, Assembly · ISO 9001 | Glendale Heights, IL | MillingTurningSwissEDMGrindingFinishingAssembly | ISO 9001 |
| Bennett Metal Products Inc Milling, Turning, Waterjet, Welding · ISO 9001, ITAR | Mount Vernon, IL | MillingTurningWaterjetWelding | ISO 9001, ITAR |
| Bland Brothers Enterprises Milling, Welding, Assembly | Springfield, IL | MillingWeldingAssembly | - |
| Burns Machine Co Milling, Turning, Bending, Welding, Grinding, Assembly · ISO 9001 | Ottawa, IL | MillingTurningBendingWeldingGrindingAssembly | ISO 9001 |