| Kaskaskia Tool and Machine, Inc Milling, Turning, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | New Athens, IL | MillingTurningBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| Acme Industries, Inc Milling, Turning, Welding, Casting · ISO 9001, AS9100 | Elk Grove Village, IL | MillingTurningWeldingCasting | ISO 9001, AS9100 |
| Alu-Bra Foundry, Inc Casting · ISO 9001 | Bensenville, IL | Casting | ISO 9001 |
| Awerkamp Machine Co Welding | Quincy, IL | Welding | - |
| B T M Industries Inc Milling, Turning, Welding, Casting, Grinding | Woodstock, IL | MillingTurningWeldingCastingGrinding | - |
| Camcraft Inc Milling, Turning, Grinding | Hanover Park, IL | MillingTurningGrinding | - |
| Cast Technologies Inc Casting | Peoria, IL | Casting | - |
| Chicago Magnesium Casting Co Welding, Casting · AS9100, NADCAP | Blue Island, IL | WeldingCasting | AS9100, NADCAP |
| Clinkenbeard & Associates Inc Milling, Casting, Assembly · AS9100, ITAR | South Beloit, IL | MillingCastingAssembly | AS9100, ITAR |
| G & Z Industries Inc Casting, EDM · ISO 9001, ITAR | Wheeling, IL | CastingEDM | ISO 9001, ITAR |
| Kris Dee and Associates, Inc Milling, Casting · ISO 9001, AS9100, ITAR | South Elgin, IL | MillingCasting | ISO 9001, AS9100, ITAR |
| Magnum Steel Works Milling, Turning, Waterjet, Bending, Welding | Mount Vernon, IL | MillingTurningWaterjetBendingWelding | - |
| Morgan Bronze Products, Inc Turning, Welding, Casting · ISO 9001 | Lake Zurich, IL | TurningWeldingCasting | ISO 9001 |
| Prismier, LLC Stamping, Casting · ISO 9001 | Bolingbrook, IL | StampingCasting | ISO 9001 |
| Smith & Richardson Manufacturing Co Milling, Stamping, Casting | Geneva, IL | MillingStampingCasting | - |
| Sonic Manufacturing Corporation Milling, Welding, EDM, Grinding, Finishing, Assembly · AS9100, NADCAP | Elk Grove Village, IL | MillingWeldingEDMGrindingFinishingAssembly | AS9100, NADCAP |
| Sycamore Precision, Inc Milling, Casting, Finishing | Genoa, IL | MillingCastingFinishing | - |