| M & R Engineering Milling, Turning, Swiss, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP | Orange, CA | MillingTurningSwissFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP |
| M&M Machining, Inc Milling, Turning, Welding, Finishing | Ventura, CA | MillingTurningWeldingFinishing | - |
| Machine Repair & Design Milling, Turning, Waterjet, Welding, Finishing, Assembly · AS9100 | Sumner, WA | MillingTurningWaterjetWeldingFinishingAssembly | AS9100 |
| Machine Specialties, LLC Milling, Turning, Swiss, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100, NADCAP | Whitsett, NC | MillingTurningSwissWeldingEDMGrindingFinishingAssembly | ISO 9001, AS9100, NADCAP |
| Machine Tool Engineering Milling, Turning, Swiss, Laser, Waterjet, Stamping, EDM, Grinding, Finishing · ISO 9001, AS9100, NADCAP | Charles City, IA | MillingTurningSwissLaserWaterjetStampingEDMGrindingFinishing | ISO 9001, AS9100, NADCAP |
| Machineworks Manufacturing Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001, AS9100, ITAR | Northridge, CA | MillingTurningLaserBendingWeldingFinishing | ISO 9001, AS9100, ITAR |
| Machining Systems Corporation Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Crestwood, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| Machinists Inc Milling, Turning, Laser, Welding, EDM, Grinding · ISO 9001, ITAR | Seattle, WA | MillingTurningLaserWeldingEDMGrinding | ISO 9001, ITAR |
| Magna Machining, Inc Milling, Turning, Finishing | Richfield, NC | MillingTurningFinishing | - |
| Magnum Machine Inc Milling, Turning, Welding, Finishing · ITAR | Raymond, NH | MillingTurningWeldingFinishing | ITAR |
| Magnum Machining LLC Milling, Turning, Finishing | Richmond, IL | MillingTurningFinishing | - |
| Majestic Metals by Fathom Manufacturing Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting, Metal AM · ISO 9001, AS9100, ITAR, ISO 13485 | Denver, CO | MillingTurningBendingLaserWeldingWaterjetEDMCastingMetal AM | ISO 9001, AS9100, ITAR, ISO 13485 |
| Manda Machine Co Milling, Turning, Laser, Welding, Waterjet, EDM · ISO 9001, AS9100 | Dallas, TX | MillingTurningLaserWeldingWaterjetEDM | ISO 9001, AS9100 |
| Manufacture.us Milling, Turning, Swiss, Laser, Finishing, Assembly | Doral, FL | MillingTurningSwissLaserFinishingAssembly | - |
| Manufacturing Solutions LLC Milling, Turning, Welding, Finishing | Tulsa, OK | MillingTurningWeldingFinishing | - |
| Marion Manufacturing Co Inc Milling, Turning, Laser, Stamping, EDM | Cheshire, CT | MillingTurningLaserStampingEDM | - |
| Maritech Machine Inc Milling, Turning, Waterjet, Welding, Grinding, Finishing · ISO 9001, AS9100 | Panama City, FL | MillingTurningWaterjetWeldingGrindingFinishing | ISO 9001, AS9100 |
| Mars Engineering Milling, Turning, Waterjet, EDM, Grinding, Finishing, Assembly | San Leandro, CA | MillingTurningWaterjetEDMGrindingFinishingAssembly | - |
| Martin's Metal Fabrication & Welding, Inc Milling, Turning, Laser, Waterjet, Bending, Welding | Vacaville, CA | MillingTurningLaserWaterjetBendingWelding | - |
| Marton Precision MF Milling, Turning, Waterjet, Welding, EDM, Finishing · ISO 9001, AS9100, ITAR | Fullerton, CA | MillingTurningWaterjetWeldingEDMFinishing | ISO 9001, AS9100, ITAR |
| Marvel Manufacturing Milling, Turning, Swiss, Welding, EDM, Grinding, Finishing | Lewiston, ID | MillingTurningSwissWeldingEDMGrindingFinishing | - |
| Masterson Industries, Inc Turning, Grinding, Finishing | Taylor, TX | TurningGrindingFinishing | - |
| 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 |
| Maxsteel Fabrication, LLC Milling, Turning, Laser, Welding, Finishing | Paris, TN | MillingTurningLaserWeldingFinishing | - |
| MBK Machine Corp Milling, Turning, Laser, EDM, Grinding · ITAR | Mead, CO | MillingTurningLaserEDMGrinding | ITAR |
| McCormick Industries Inc Milling, Turning, Swiss, Welding, Grinding, Finishing, Assembly · ISO 9001 | Appleton, WI | MillingTurningSwissWeldingGrindingFinishingAssembly | ISO 9001 |
| McKiney Manufacturing Milling, Turning, Laser, Waterjet, Bending, Welding | Mitchell, NE | MillingTurningLaserWaterjetBendingWelding | - |
| Mechfi Designs LLC Milling, Turning, Finishing | Westminster, CO | MillingTurningFinishing | - |
| Menze Precision Machining, LLC Milling, Turning, Bending, Welding, EDM, Grinding, Finishing | Winter Haven, FL | MillingTurningBendingWeldingEDMGrindingFinishing | - |
| Mercury Machine Works LLC Milling, Turning, Laser, Finishing · ISO 9001, ITAR | Spring, TX | MillingTurningLaserFinishing | ISO 9001, ITAR |
| Meridian Manufacturing Inc Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Ballston Spa, NY | MillingTurningLaserWeldingEDMGrindingFinishing | - |
| 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 |
| Metal Workz L.L.C Milling, Turning, Laser, Bending, Welding, Finishing | Albany, KY | MillingTurningLaserBendingWeldingFinishing | - |
| Metalogic Industries LLC Milling, Turning, Swiss, Laser, Welding, EDM, Grinding | Southbridge, MA | MillingTurningSwissLaserWeldingEDMGrinding | - |
| Metalquest Unlimited, Inc Milling, Turning, Finishing, Assembly | Hebron, NE | MillingTurningFinishingAssembly | - |
| MF Engineering Company, Inc Milling, Turning, Swiss, Welding, Grinding, Finishing · ISO 9001, NADCAP | Bristol, RI | MillingTurningSwissWeldingGrindingFinishing | ISO 9001, NADCAP |
| Mico Welding & Machining, Inc Milling, Turning, Welding, Finishing | Nine Mile Falls, WA | MillingTurningWeldingFinishing | - |
| Micro-Tec, Inc Milling, Turning, Welding, EDM, Finishing · ISO 9001, AS9100 | Chatsworth, CA | MillingTurningWeldingEDMFinishing | ISO 9001, AS9100 |
| Microform Precision LLC Turning, Bending, Laser, Welding, Waterjet | Sacramento, CA | TurningBendingLaserWeldingWaterjet | - |
| Mid-Continent Machining Inc Milling, Turning, Welding, Finishing | Kansas City, KS | MillingTurningWeldingFinishing | - |
| Midway Machine & Instrument Company Inc Milling, Turning, EDM, Finishing · ISO 9001 | South Houston, TX | MillingTurningEDMFinishing | ISO 9001 |
| Midway Swiss Turn, Inc Milling, Turning, Swiss, Finishing, Assembly · CMMC | Wooster, OH | MillingTurningSwissFinishingAssembly | CMMC |
| Midwest Industrial Metal Fabrication Inc Milling, Turning, Punching, Bending, Welding, Stamping, Finishing | Huntington, IN | MillingTurningPunchingBendingWeldingStampingFinishing | - |
| Midwest Precision Machining Milling, Turning, Swiss, Grinding, Finishing · AS9100, NADCAP | Monticello, MN | MillingTurningSwissGrindingFinishing | AS9100, NADCAP |
| Mikron Manufacturing Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Colorado Springs, CO | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| Miller Metal Fabrication Inc Turning, Laser, Punching, Welding · ISO 9001 | Bridgeville, DE | TurningLaserPunchingWelding | ISO 9001 |
| Milo Engineering Milling, Turning, Grinding, Finishing · ISO 9001 | Torrance, CA | MillingTurningGrindingFinishing | ISO 9001 |
| MMG Corp Milling, Turning, Finishing, Assembly · ISO 9001 | Ontario, CA | MillingTurningFinishingAssembly | ISO 9001 |