| Lamjen Inc Milling, Turning, Welding, Stamping, Casting · ISO 9001 | Erie, PA | MillingTurningWeldingStampingCasting | ISO 9001 |
| Leiss Tool & Die Co Milling, Turning, Bending, Welding, Stamping, EDM, Grinding | Somerset, PA | MillingTurningBendingWeldingStampingEDMGrinding | - |
| Leister Machine LLC Milling, Welding | Bedford, PA | MillingWelding | - |
| M & B Machine, Inc Milling, Turning, Swiss, Welding · ISO 9001, AS9100, CMMC | Carlisle, PA | MillingTurningSwissWelding | ISO 9001, AS9100, CMMC |
| M & M Sheet Metal, Inc Milling, Laser, Bending, Welding, Forging · ISO 9001, ITAR, CMMC | Williamsport, PA | MillingLaserBendingWeldingForging | ISO 9001, ITAR, CMMC |
| Machined Products Co Turning, Welding · ISO 9001 | Lancaster, PA | TurningWelding | ISO 9001 |
| Machining Tech Milling, Turning, Waterjet, Welding, Stamping, EDM, Grinding | Hazle Township, PA | MillingTurningWaterjetWeldingStampingEDMGrinding | - |
| Max Machine Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing · ISO 9001 | Elizabethtown, PA | MillingTurningLaserWaterjetWeldingGrindingFinishing | ISO 9001 |
| Max Machining LLC Milling, Turning, Laser, Bending · ITAR, CMMC | Telford, PA | MillingTurningLaserBending | ITAR, CMMC |
| Metplas Inc Milling, Turning, Waterjet, Punching, Bending, Assembly · ISO 9001 | Natrona Heights, PA | MillingTurningWaterjetPunchingBendingAssembly | ISO 9001 |
| Micro Facture LLC Milling, Turning, EDM, Grinding, Assembly · ISO 9001, ITAR | Lancaster, PA | MillingTurningEDMGrindingAssembly | ISO 9001, ITAR |
| Mission Critical Solutions LLC Milling, Punching, Bending, Welding | Alum Bank, PA | MillingPunchingBendingWelding | - |
| Montgomery Dynamics Milling, Turning, Welding · ISO 9001, ITAR | Huntingdon Valley, PA | MillingTurningWelding | ISO 9001, ITAR |
| Motive Machine Works LLC Milling, Turning, Stamping, Finishing, Assembly | Lancaster, PA | MillingTurningStampingFinishingAssembly | - |
| Navitek Machining Corp Milling, Turning, EDM, Grinding, Assembly · AS9100, ISO 13485 | Fairview, PA | MillingTurningEDMGrindingAssembly | AS9100, ISO 13485 |
| Niagara Manufacturing Co Milling, Turning, Bending, Welding | Erie, PA | MillingTurningBendingWelding | - |
| Olympic Tool & Machine Corp Milling, Grinding, Assembly | Aston, PA | MillingGrindingAssembly | - |
| Olympus Machining Milling, Turning · ITAR, CMMC | Hanover, PA | MillingTurning | ITAR, CMMC |
| Painter Tool Incorporated Milling, Turning, Welding, EDM | Irwin, PA | MillingTurningWeldingEDM | - |
| PBZ Manufacturing Laser, Bending, Welding, Finishing · ISO 9001 | Lititz, PA | LaserBendingWeldingFinishing | ISO 9001 |
| Penn Metal Fabricators Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing · ISO 9001 | Ebensburg, PA | MillingTurningLaserPunchingBendingWeldingFinishing | ISO 9001 |
| Perseo-Erie Machine Sales Milling, Laser, EDM, Stamping | Erie, PA | MillingLaserEDMStamping | - |
| Qmac-Quality Machining Inc Milling, Turning, Waterjet, Punching, Welding, Finishing · ITAR | Bellefonte, PA | MillingTurningWaterjetPunchingWeldingFinishing | ITAR |
| Reynolds Machine Co Milling, Turning · AS9100 | Ruffs Dale, PA | MillingTurning | AS9100 |
| RGS Machine Inc Milling, Turning, Swiss · ISO 9001 | Folsom, PA | MillingTurningSwiss | ISO 9001 |
| Rinval Manufacturing Laser | Indiana, PA | Laser | - |
| RJC Manufacturing Services LLC Milling, Turning, Bending, Welding | Irwin, PA | MillingTurningBendingWelding | - |
| Schred Machine Company, Inc Milling, Turning · AS9100 | Warminster, PA | MillingTurning | AS9100 |
| Sepco Erie Milling, Turning, Stamping · ISO 9001 | Erie, PA | MillingTurningStamping | ISO 9001 |
| SJD Machining, Inc Milling, Turning, EDM, Grinding, Finishing | Meadville, PA | MillingTurningEDMGrindingFinishing | - |
| Starlite Diversified Inc Milling, Turning, Welding, EDM, Grinding | Meadville, PA | MillingTurningWeldingEDMGrinding | - |
| Steel Valley Fabricators, LLC Milling, Bending, Welding | Braddock, PA | MillingBendingWelding | - |
| Sterling Machine Technologies Turning, Bending, Welding | Palmyra, PA | TurningBendingWelding | - |
| T-Tygart Industries, Inc Milling, Turning, Bending, Welding, Grinding | Carmichaels, PA | MillingTurningBendingWeldingGrinding | - |
| The Charles Schillinger Co., Inc Turning, Welding, Stamping · ISO 9001 | Bensalem, PA | TurningWeldingStamping | ISO 9001 |
| 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 |
| Three Rivers Precision, LLC Welding, Assembly · ISO 9001 | East Liberty, PA | WeldingAssembly | ISO 9001 |
| US Anodize Finishing · NADCAP | Reading, PA | Finishing | NADCAP |
| US Axle, Inc Milling, Forging, Grinding | Pottstown, PA | MillingForgingGrinding | - |
| Vptt Armaments Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, ITAR | Tower City, PA | MillingTurningLaserWaterjetBendingWeldingStampingEDMGrindingAssembly | ISO 9001, ITAR |
| Zober Industries, Inc Milling, Turning, Welding, EDM, Assembly · ISO 9001, ISO 13485 | Croydon, PA | MillingTurningWeldingEDMAssembly | ISO 9001, ISO 13485 |