| Metalquest Unlimited, Inc Milling, Turning, Finishing, Assembly | Hebron, NE | MillingTurningFinishingAssembly | - |
| Metco Metal Fab. Bending, Laser, Welding | Chattanooga, TN | BendingLaserWelding | - |
| 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 Inc Bending, Laser, Welding, Waterjet · ISO 9001 | Tulsa, OK | BendingLaserWeldingWaterjet | ISO 9001 |
| 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 |
| Millennium Metalcraft, Inc Milling, Laser, Bending, Welding, Finishing, Assembly · ISO 9001 | Fremont, CA | MillingLaserBendingWeldingFinishingAssembly | ISO 9001 |
| 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 |
| MJM Manufacturing Inc Milling, Laser, Punching, Bending, Welding, Stamping · ISO 9001, AS9100, ITAR | Miami Lakes, FL | MillingLaserPunchingBendingWeldingStamping | ISO 9001, AS9100, ITAR |
| MKM Manufacturing & Design, Inc Finishing | Newbury Park, CA | Finishing | - |
| MMG Corp Milling, Turning, Finishing, Assembly · ISO 9001 | Ontario, CA | MillingTurningFinishingAssembly | ISO 9001 |
| Mofab Inc Milling, Laser, Waterjet, Bending, Welding | Anderson, IN | MillingLaserWaterjetBendingWelding | - |
| Mojo Masters LLC Milling, Laser, Bending, EDM, Grinding | Vestal, NY | MillingLaserBendingEDMGrinding | - |
| Monsees Tool & Die Inc Milling, Turning, EDM, Grinding, Finishing | Rochester, NY | MillingTurningEDMGrindingFinishing | - |
| Moore Tool Company, Inc Stamping, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Bridgeport, CT | StampingGrindingFinishingAssembly | ISO 9001, AS9100 |
| Morrison Industries LLC Milling, Turning, Laser, Bending, Welding, Finishing, Assembly | Morrison, TN | MillingTurningLaserBendingWeldingFinishingAssembly | - |
| Motion Metalworks LLC Laser, Waterjet, Bending, Welding, Finishing | Wrens, GA | LaserWaterjetBendingWeldingFinishing | - |
| Mountain CNC Milling, Turning, Waterjet, Welding, Grinding, Finishing, Assembly · ITAR, CMMC | Loveland, CO | MillingTurningWaterjetWeldingGrindingFinishingAssembly | ITAR, CMMC |
| Mountain Manufacturing, LLC Milling, Laser, Bending, Welding, Finishing, Assembly · ISO 13485 | Post Falls, ID | MillingLaserBendingWeldingFinishingAssembly | ISO 13485 |
| 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 | - |
| Murphy Machine Products, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001 | Wood Dale, IL | MillingTurningSwissGrindingFinishing | ISO 9001 |
| Music City Sheet Metal Bending, Laser, Welding | Nashville, TN | BendingLaserWelding | - |
| 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 | - |
| Neff Engineering LLC Milling, Laser, Welding | Los Angeles, CA | MillingLaserWelding | - |
| 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 London Precision Instruments Inc Milling, Waterjet, EDM, Grinding, Finishing | New Market, MD | MillingWaterjetEDMGrindingFinishing | - |
| New Method Steel Stamps Inc Milling, Turning, Laser, Bending, Stamping · ISO 9001 | Fraser, MI | MillingTurningLaserBendingStamping | ISO 9001 |
| 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 |
| Nor-Ell Inc Stamping, Finishing · NADCAP | Saint Paul, MN | StampingFinishing | NADCAP |
| Noron Precision Machining Inc Milling, Turning, Grinding, Finishing, Assembly · ISO 9001, ITAR | Sunnyvale, CA | MillingTurningGrindingFinishingAssembly | ISO 9001, ITAR |
| Nortek, Inc Milling, Turning, Swiss, Laser, Waterjet, Welding, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR, NADCAP | West Springfield, MA | MillingTurningSwissLaserWaterjetWeldingEDMGrindingFinishing | ISO 9001, AS9100, ITAR, NADCAP |
| North Country Engineering Inc Milling, Turning, Laser, Grinding · ISO 9001, AS9100, ITAR | Derby, VT | MillingTurningLaserGrinding | ISO 9001, AS9100, ITAR |
| North Second Street Steel Laser, Welding | Minneapolis, MN | LaserWelding | - |
| Northway Mathers Inc Milling, Turning, Waterjet, Bending, Welding, Finishing | Mukilteo, WA | MillingTurningWaterjetBendingWeldingFinishing | - |