| Q Company, LLC Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100, ITAR | New Berlin, PA | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100, ITAR |
| Reisinger Automation & Design LLC Milling, Turning, Waterjet, Welding, Grinding, Finishing | Reading, PA | MillingTurningWaterjetWeldingGrindingFinishing | - |
| Reuss Industries, Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Madison, PA | MillingTurningWaterjetWeldingEDMGrinding | - |
| Shoemaker Mfg Solutions Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping, Grinding · ISO 9001, AS9100, ITAR, CMMC | Souderton, PA | MillingTurningLaserWaterjetPunchingBendingWeldingStampingGrinding | ISO 9001, AS9100, ITAR, CMMC |
| SJD Machining, Inc Milling, Turning, EDM, Grinding, Finishing | Meadville, PA | MillingTurningEDMGrindingFinishing | - |
| Skytop Machine and Tool, Inc Milling, Turning, Waterjet, Welding, Grinding | Port Matilda, PA | MillingTurningWaterjetWeldingGrinding | - |
| Specialty Roller and Machine Inc Milling, Turning, Grinding | Berwick, PA | MillingTurningGrinding | - |
| Starlite Diversified Inc Milling, Turning, Welding, EDM, Grinding | Meadville, PA | MillingTurningWeldingEDMGrinding | - |
| Starn Tool & Manufacturing Company Milling, Turning, EDM, Grinding, Finishing · ISO 9001, ITAR | Meadville, PA | MillingTurningEDMGrindingFinishing | ISO 9001, ITAR |
| Steer Machine Tool and Die Corporation Milling, Turning, Welding, Grinding | Honesdale, PA | MillingTurningWeldingGrinding | - |
| Stellar Precision Components. Ltd Milling, Turning, EDM, Grinding · ISO 9001, AS9100 | Jeannette, PA | MillingTurningEDMGrinding | ISO 9001, AS9100 |
| T-Tygart Industries, Inc Milling, Turning, Bending, Welding, Grinding | Carmichaels, PA | MillingTurningBendingWeldingGrinding | - |
| The Flinchbaugh Company, Inc Milling, Turning, Welding, EDM, Grinding, Finishing, Assembly | Manchester, PA | MillingTurningWeldingEDMGrindingFinishingAssembly | - |
| Thomas W Springer Inc Milling, Turning, Swiss, Welding, Grinding · ISO 9001 | Landenberg, PA | MillingTurningSwissWeldingGrinding | ISO 9001 |
| US Axle, Inc Milling, Forging, Grinding | Pottstown, PA | MillingForgingGrinding | - |
| Venango Machine Company, Inc Milling, Welding, Grinding · ISO 9001 | Wattsburg, PA | MillingWeldingGrinding | ISO 9001 |
| Vptt Armaments Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, ITAR | Tower City, PA | MillingTurningLaserWaterjetBendingWeldingStampingEDMGrindingAssembly | ISO 9001, ITAR |