| Quality Engineering Services Inc Milling, Turning, Welding, EDM, Grinding · ISO 9001, ITAR | Wallingford, CT | MillingTurningWeldingEDMGrinding | ISO 9001, ITAR |
| Saar Corp Milling, Turning, Swiss, Finishing, Assembly · AS9100 | Farmington, CT | MillingTurningSwissFinishingAssembly | AS9100 |
| Skillcraft Machine Tool Co Inc Milling, Turning, Welding | South Windsor, CT | MillingTurningWelding | - |
| Straitek, LLC Milling, Bending, Finishing · ITAR, ISO 13485 | Danbury, CT | MillingBendingFinishing | ITAR, ISO 13485 |
| T.e.t. Mfg. Co Inc Milling, Grinding, Finishing | Middlefield, CT | MillingGrindingFinishing | - |
| Troy Industrial Milling | Ansonia, CT | Milling | - |
| U.S. Fabricating LLC Assembly | Naugatuck, CT | Assembly | - |
| Valley Tool and Manufacturing LLC Milling, Turning, Waterjet, Bending, Welding, EDM, Assembly · NADCAP | Milford, CT | MillingTurningWaterjetBendingWeldingEDMAssembly | NADCAP |
| W & W Machine Co Inc Milling, Turning, Swiss, Welding, EDM, Finishing | Milford, CT | MillingTurningSwissWeldingEDMFinishing | - |
| Yankee Casting Co, Inc Milling, Welding, Casting · AS9100, NADCAP | Enfield, CT | MillingWeldingCasting | AS9100, NADCAP |
| Zike Industries LLC Milling, Turning, Laser, Welding, Finishing | Tolland, CT | MillingTurningLaserWeldingFinishing | - |