| Marvel Manufacturing Milling, Turning, Swiss, Welding, EDM, Grinding, Finishing | Lewiston, ID | MillingTurningSwissWeldingEDMGrindingFinishing | - |
| Maryland Greater Tool & Manufacturing Milling, Turning, Waterjet, Welding, Grinding, Finishing | Mountain Lake Park, MD | MillingTurningWaterjetWeldingGrindingFinishing | - |
| Max Machine Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing · ISO 9001 | Elizabethtown, PA | MillingTurningLaserWaterjetWeldingGrindingFinishing | ISO 9001 |
| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| McCallin Steel Storage Systems, Inc Milling, Punching, Welding, Finishing | Commerce City, CO | MillingPunchingWeldingFinishing | - |
| McCormick Industries Inc Milling, Turning, Swiss, Welding, Grinding, Finishing, Assembly · ISO 9001 | Appleton, WI | MillingTurningSwissWeldingGrindingFinishingAssembly | ISO 9001 |
| 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 | - |
| Met International Trading Company, Inc Laser, Punching, Bending, Welding, Finishing | Houston, TX | LaserPunchingBendingWeldingFinishing | - |
| 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 | - |
| Metalbuilt LLC Milling, Turning, Laser, Welding, Stamping, Finishing · ISO 9001, AS9100, IATF 16949 | Chesterfield, MI | MillingTurningLaserWeldingStampingFinishing | ISO 9001, AS9100, IATF 16949 |
| Metalmasters Milling, Turning, Bending, Welding, Finishing | Brighton, CO | MillingTurningBendingWeldingFinishing | - |
| 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 |
| Mid-Continent Engineering, LLC Bending, Welding, Grinding, Finishing · ISO 9001, AS9100, ITAR | Minneapolis, MN | BendingWeldingGrindingFinishing | ISO 9001, AS9100, ITAR |
| 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 |
| Mikron Manufacturing Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Colorado Springs, CO | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| Miramar Metal Processing Inc Welding, Finishing · ITAR, NADCAP | San Diego, CA | WeldingFinishing | ITAR, NADCAP |
| MMG Corp Milling, Turning, Finishing, Assembly · ISO 9001 | Ontario, CA | MillingTurningFinishingAssembly | ISO 9001 |
| Modern Machine Works Milling, Turning, Welding, EDM, Grinding, Finishing | Albany, OR | MillingTurningWeldingEDMGrindingFinishing | - |
| Monsees Tool & Die Inc Milling, Turning, EDM, Grinding, Finishing | Rochester, NY | MillingTurningEDMGrindingFinishing | - |
| Moria Manufacturing LLC Milling, Turning, Finishing | Monona, WI | MillingTurningFinishing | - |
| Morrison Industries LLC Milling, Turning, Laser, Bending, Welding, Finishing, Assembly | Morrison, TN | MillingTurningLaserBendingWeldingFinishingAssembly | - |
| Motive Machine Works LLC Milling, Turning, Stamping, Finishing, Assembly | Lancaster, PA | MillingTurningStampingFinishingAssembly | - |
| Mountain CNC Milling, Turning, Waterjet, Welding, Grinding, Finishing, Assembly · ITAR, CMMC | Loveland, CO | MillingTurningWaterjetWeldingGrindingFinishingAssembly | ITAR, CMMC |
| Mountain Precision Tool Co, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, EDM, Grinding, Finishing | Blacksburg, VA | MillingTurningLaserWaterjetPunchingBendingWeldingEDMGrindingFinishing | - |
| MSP Maufacturing Milling, Turning, Bending, Welding, Finishing, Assembly | Bloomington, IN | MillingTurningBendingWeldingFinishingAssembly | - |
| Mueller Machining LLC Milling, Turning, Laser, Bending, Grinding, Finishing | Salem, OR | MillingTurningLaserBendingGrindingFinishing | - |
| Multi-Machining Co Inc Milling, Turning, Finishing, Assembly | Greenville, TX | MillingTurningFinishingAssembly | - |
| Multisource Manufacturing LLC Milling, Turning, Swiss, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | Minneapolis, MN | MillingTurningSwissEDMGrindingFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |
| N.e.t. & Die, Inc Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing | Fulton, NY | MillingTurningLaserWaterjetWeldingGrindingFinishing | - |
| Naimor Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly | Snohomish, WA | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | - |
| Natoma Manufacturing, LLC Milling, Turning, Swiss, Finishing · ISO 9001, AS9100, NADCAP | Norton, KS | MillingTurningSwissFinishing | ISO 9001, AS9100, NADCAP |
| Nebraska Machine Products, Inc Turning, Welding, Grinding, Finishing | Omaha, NE | TurningWeldingGrindingFinishing | - |
| Netzer Metalworks, LLC Milling, Punching, Bending, Welding, Finishing, Assembly · NADCAP | Essex, MD | MillingPunchingBendingWeldingFinishingAssembly | NADCAP |
| New Age Manufacturing, Inc Milling, Turning, Welding, Grinding, Finishing, Assembly · ISO 9001 | Plattsmouth, NE | MillingTurningWeldingGrindingFinishingAssembly | ISO 9001 |
| New Brunswick Plating Inc Milling, Casting, Finishing · ISO 9001, AS9100, NADCAP | New Brunswick, NJ | MillingCastingFinishing | ISO 9001, AS9100, NADCAP |
| New England Foundry LLC Milling, Bending, Welding, Stamping, Casting, EDM, Grinding, Finishing · ISO 9001 | Taunton, MA | MillingBendingWeldingStampingCastingEDMGrindingFinishing | ISO 9001 |
| New Tech Metals Milling, Turning, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly · ISO 9001, AS9100, ITAR, IATF 16949, CMMC | Green Bay, WI | MillingTurningLaserPunchingBendingWeldingStampingFinishingAssembly | ISO 9001, AS9100, ITAR, IATF 16949, CMMC |
| Neway Stamping & Manufacturing, Inc Laser, Stamping, Finishing | Willoughby, OH | LaserStampingFinishing | - |
| Next Tech Manufacturing Inc Milling, Welding, Finishing | Santa Clara, CA | MillingWeldingFinishing | - |
| NJ Precision Technologies Inc Milling, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | Mountainside, NJ | MillingWeldingStampingEDMFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |