| JC Macelroy Co Inc Milling, Punching, Bending, Welding, Grinding, Assembly | Piscataway, NJ | MillingPunchingBendingWeldingGrindingAssembly | - |
| JC Tool & Die, LLC Milling, Turning, Stamping, EDM, Grinding, Assembly · ISO 9001, ITAR | Hull, GA | MillingTurningStampingEDMGrindingAssembly | ISO 9001, ITAR |
| Jerl Machine Inc Milling, Turning, Welding, Casting, EDM, Grinding, Assembly · ISO 9001 | Perrysburg, OH | MillingTurningWeldingCastingEDMGrindingAssembly | ISO 9001 |
| Jetsons Precision Cleaning LLC Finishing, Assembly · ISO 9001, AS9100, ISO 13485 | Garner, NC | FinishingAssembly | ISO 9001, AS9100, ISO 13485 |
| JMT Machine Company Milling, Turning, Assembly | Huntingdon Valley, PA | MillingTurningAssembly | - |
| Joined Alloys Welding, EDM, Assembly · ISO 9001, NADCAP | Phoenix, AZ | WeldingEDMAssembly | ISO 9001, NADCAP |
| Jones Co Machining Milling, Turning, Welding, Assembly | Hannibal, MO | MillingTurningWeldingAssembly | - |
| K&M Milling, Turning, Laser, Welding, Assembly · ISO 9001 | Cassopolis, MI | MillingTurningLaserWeldingAssembly | ISO 9001 |
| Kammerer Dynamics Inc Laser, Bending, Welding, Casting, Finishing, Assembly | Kendallville, IN | LaserBendingWeldingCastingFinishingAssembly | - |
| Kennebec Technologies Milling, Grinding, Assembly | Augusta, ME | MillingGrindingAssembly | - |
| KLW Manufacturing & Design, Inc Milling, Assembly | Arlington, WA | MillingAssembly | - |
| Knox Machine Co Assembly · ISO 9001, AS9100, ITAR | Warren, ME | Assembly | ISO 9001, AS9100, ITAR |
| Kocsis Brothers Machine Company Welding, Assembly | Alsip, IL | WeldingAssembly | - |
| Krametech, Inc Milling, Finishing, Assembly | Lake Zurich, IL | MillingFinishingAssembly | - |
| Laserform & Machine Inc Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Columbia, SC | TurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Leanwerks, LLC Milling, Turning, Welding, Casting, Grinding, Assembly · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningWeldingCastingGrindingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Lektron Inc Milling, EDM, Assembly | Hartselle, AL | MillingEDMAssembly | - |
| LHM Engineering LLC Milling, Swiss, Laser, Waterjet, Stamping, EDM, Grinding, Finishing, Assembly · ISO 13485 | Manchester, MA | MillingSwissLaserWaterjetStampingEDMGrindingFinishingAssembly | ISO 13485 |
| Lincoln Tool & Machine Corp Milling, Assembly | Hudson, MA | MillingAssembly | - |
| Lodolce Machine Co, Inc Milling, Turning, Laser, Welding, EDM, Assembly · ISO 9001, AS9100 | Saugerties, NY | MillingTurningLaserWeldingEDMAssembly | ISO 9001, AS9100 |
| M & S Machining Inc Milling, Turning, Bending, Welding, EDM, Assembly · ISO 9001, AS9100, ITAR | Winchester, KY | MillingTurningBendingWeldingEDMAssembly | ISO 9001, AS9100, ITAR |
| M.a. Metal Co., Inc Laser, Bending, Welding, Stamping, Assembly · ISO 9001 | Columbus, IN | LaserBendingWeldingStampingAssembly | ISO 9001 |
| Machine Repair & Design Milling, Turning, Waterjet, Welding, Finishing, Assembly · AS9100 | Sumner, WA | MillingTurningWaterjetWeldingFinishingAssembly | AS9100 |
| Machine Shop LLC EDM, Assembly | East Hardwick, VT | EDMAssembly | - |
| Mars Engineering Milling, Turning, Waterjet, EDM, Grinding, Finishing, Assembly | San Leandro, CA | MillingTurningWaterjetEDMGrindingFinishingAssembly | - |
| Mass Precision Inc Welding, Assembly · ISO 9001, ISO 13485 | San Jose, CA | WeldingAssembly | ISO 9001, ISO 13485 |
| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| Mdi Manufacturing Inc Milling, Turning, Welding, Grinding, Assembly · ISO 9001 | Lakewood, NJ | MillingTurningWeldingGrindingAssembly | ISO 9001 |
| Metal Components LLC Turning, Waterjet, Bending, Welding, Finishing, Assembly · ISO 9001 | Grand Rapids, MI | TurningWaterjetBendingWeldingFinishingAssembly | ISO 9001 |
| Metal Essence Inc Milling, Turning, Swiss, Finishing, Assembly · ISO 9001, AS9100, ITAR | Longwood, FL | MillingTurningSwissFinishingAssembly | ISO 9001, AS9100, ITAR |
| Metaltech Inc Laser, Bending, Welding, Assembly · AS9100 | Auburn, WA | LaserBendingWeldingAssembly | AS9100 |
| 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 |
| Micro-Matics Inc Milling, Turning, Swiss, Casting, EDM, Grinding, Assembly | Fridley, MN | MillingTurningSwissCastingEDMGrindingAssembly | - |
| Midwest Machining Solutions LLC Milling, Turning, Waterjet, Welding, Assembly | Saint Louis, MO | MillingTurningWaterjetWeldingAssembly | - |
| Millennium Metalcraft, Inc Milling, Laser, Bending, Welding, Finishing, Assembly · ISO 9001 | Fremont, CA | MillingLaserBendingWeldingFinishingAssembly | ISO 9001 |
| Mountain CNC Milling, Turning, Waterjet, Welding, Grinding, Finishing, Assembly · ITAR, CMMC | Loveland, CO | MillingTurningWaterjetWeldingGrindingFinishingAssembly | ITAR, CMMC |
| Mountain Defense LLC Milling, Turning, EDM, Assembly | Mentor, OH | MillingTurningEDMAssembly | - |
| MST Manufacturing LLC Milling, Turning, Bending, Welding, Assembly · ISO 9001, AS9100, ITAR, CMMC | Claremore, OK | MillingTurningBendingWeldingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Navitek Machining Corp Milling, Turning, EDM, Grinding, Assembly · AS9100, ISO 13485 | Fairview, PA | MillingTurningEDMGrindingAssembly | AS9100, ISO 13485 |
| Nikel Precision Group LLC Milling, Turning, Grinding, Assembly · ISO 13485 | Saco, ME | MillingTurningGrindingAssembly | ISO 13485 |
| NRL & Associates Inc Milling, Turning, Bending, Welding, Assembly | Stevensville, MD | MillingTurningBendingWeldingAssembly | - |
| Numericraft, Inc Milling, Turning, Finishing, Assembly | Tucson, AZ | MillingTurningFinishingAssembly | - |
| Nusource, LLC Welding, Assembly | Alexandria, VA | WeldingAssembly | - |
| Oakes Manufacturing LLC Milling, Turning, Assembly · ISO 9001 | Fort Collins, CO | MillingTurningAssembly | ISO 9001 |
| Octal Corporation Milling, Turning, Welding, Grinding, Assembly · ISO 9001, AS9100 | Teaneck, NJ | MillingTurningWeldingGrindingAssembly | ISO 9001, AS9100 |
| Olympic Tool & Machine Corp Milling, Grinding, Assembly | Aston, PA | MillingGrindingAssembly | - |
| Onium Machine and Fabrication, LLC Milling, Turning, Laser, Bending, Welding, Assembly · ISO 9001 | Winder, GA | MillingTurningLaserBendingWeldingAssembly | ISO 9001 |
| Parallax Manufacturing LLC Milling, Turning, Bending, Welding, Stamping, Assembly · NADCAP | Lake Elsinore, CA | MillingTurningBendingWeldingStampingAssembly | NADCAP |
| PDS Milling, Turning, Swiss, Finishing, Assembly · ISO 9001 | Minneapolis, MN | MillingTurningSwissFinishingAssembly | ISO 9001 |