| Metalcraft Inc Bending, Laser, Welding | Boise, ID | BendingLaserWelding | - |
| Metalcraft Services Of Tampa, LLC. Bending, Welding, Waterjet, Stamping | Tampa, FL | BendingWeldingWaterjetStamping | - |
| Metalcrafters, Inc Stamping, Assembly · ISO 9001, ITAR | Methuen, MA | StampingAssembly | ISO 9001, ITAR |
| MetalMania Bending, Laser, Welding | Brooklyn, NY | BendingLaserWelding | - |
| Metalmasters Milling, Turning, Bending, Welding, Finishing | Brighton, CO | MillingTurningBendingWeldingFinishing | - |
| Metalogic Industries LLC Milling, Turning, Swiss, Laser, Welding, EDM, Grinding | Southbridge, MA | MillingTurningSwissLaserWeldingEDMGrinding | - |
| Metco Metal Fab. Bending, Laser, Welding | Chattanooga, TN | BendingLaserWelding | - |
| Metplas Inc Milling, Turning, Waterjet, Punching, Bending, Assembly · ISO 9001 | Natrona Heights, PA | MillingTurningWaterjetPunchingBendingAssembly | ISO 9001 |
| Metro Machine Inc Milling, Turning, Grinding · ISO 9001, AS9100, ITAR | Englewood, CO | MillingTurningGrinding | ISO 9001, AS9100, ITAR |
| Meyer Tool & Manufacturing, Inc Milling, Turning, Welding · ITAR | Oak Lawn, IL | MillingTurningWelding | ITAR |
| Mgi/metalagraphics Milling, Turning | Moorpark, CA | MillingTurning | - |
| Microform Precision LLC Turning, Bending, Laser, Welding, Waterjet | Sacramento, CA | TurningBendingLaserWeldingWaterjet | - |
| Micron Precision Machining Inc Milling, Turning, EDM, Grinding | Saginaw, MI | MillingTurningEDMGrinding | - |
| Mid-State Metals Bending, Welding | Orlando, FL | BendingWelding | - |
| Midlake Products & Mfg. Co., Inc Turning, Bending, Laser, Welding, Stamping | Canton, OH | TurningBendingLaserWeldingStamping | - |
| Midwest Machining Solutions LLC Milling, Turning, Waterjet, Welding, Assembly | Saint Louis, MO | MillingTurningWaterjetWeldingAssembly | - |
| Midwest Precision Inc Bending, Laser, Welding, Waterjet · ISO 9001 | Tulsa, OK | BendingLaserWeldingWaterjet | ISO 9001 |
| Midwest Tool Inc Milling, Turning, Welding, EDM, Grinding | Joplin, MO | MillingTurningWeldingEDMGrinding | - |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| 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 |
| Millwood Metalworks Punching, Bending, Welding | Freeport, MN | PunchingBendingWelding | - |
| Milwaukee Metal Products Co Bending, Welding, Stamping | Milwaukee, WI | BendingWeldingStamping | - |
| Mission Critical Solutions LLC Milling, Punching, Bending, Welding | Alum Bank, PA | MillingPunchingBendingWelding | - |
| MJM Manufacturing Inc Milling, Laser, Punching, Bending, Welding, Stamping · ISO 9001, AS9100, ITAR | Miami Lakes, FL | MillingLaserPunchingBendingWeldingStamping | ISO 9001, AS9100, ITAR |
| MM Industries Tech LLC Laser, Punching, Bending, Welding, Assembly | Stanwood, WA | LaserPunchingBendingWeldingAssembly | - |
| Mofab Inc Milling, Laser, Waterjet, Bending, Welding | Anderson, IN | MillingLaserWaterjetBendingWelding | - |
| Moll Machine Works, LLC Milling, Turning, Welding | Williamson, NY | MillingTurningWelding | - |
| Monarch Valve Corp Milling, Turning, Welding, Grinding, Assembly · ISO 9001 | Aston, PA | MillingTurningWeldingGrindingAssembly | ISO 9001 |
| Mono Engineering Corp Turning, Welding, EDM · ISO 9001 | Chatsworth, CA | TurningWeldingEDM | ISO 9001 |
| Montgomery Dynamics Milling, Turning, Welding · ISO 9001, ITAR | Huntingdon Valley, PA | MillingTurningWelding | ISO 9001, ITAR |
| Morena Welding Inc Welding | San Diego, CA | Welding | - |
| Morrison Berkshire Inc Welding | North Adams, MA | Welding | - |
| Motion Metalworks LLC Laser, Waterjet, Bending, Welding, Finishing | Wrens, GA | LaserWaterjetBendingWeldingFinishing | - |
| MSP Maufacturing Milling, Turning, Bending, Welding, Finishing, Assembly | Bloomington, IN | MillingTurningBendingWeldingFinishingAssembly | - |
| Music City Sheet Metal Bending, Laser, Welding | Nashville, TN | BendingLaserWelding | - |
| Napoleon Machine LLC Milling, Bending, Welding, Forging, Grinding · ISO 9001, ITAR, CMMC | Napoleon, OH | MillingBendingWeldingForgingGrinding | ISO 9001, ITAR, CMMC |
| NCX Concepts LLC Milling, Welding · ITAR | Charlotte, NC | MillingWelding | ITAR |
| Nelgo Manufacturing Co Milling, Turning, Punching, Welding · ISO 9001, AS9100, ITAR | Oceanside, CA | MillingTurningPunchingWelding | ISO 9001, AS9100, ITAR |
| Neosource, Inc. Milling, Welding, Waterjet · ISO 9001, AS9100 | Tulsa, OK | MillingWeldingWaterjet | ISO 9001, AS9100 |
| Nevron Plastics Inc Turning, Punching · ISO 9001 | Saugus, MA | TurningPunching | 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 |
| Nexus Automation Milling, Welding, EDM, Assembly · ISO 9001, ITAR, ISO 13485 | Livermore, CA | MillingWeldingEDMAssembly | ISO 9001, ITAR, ISO 13485 |
| Nikel Precision Group LLC Milling, Turning, Grinding, Assembly · ISO 13485 | Saco, ME | MillingTurningGrindingAssembly | ISO 13485 |
| NKP Metals LLC Waterjet, Welding | Chicago, IL | WaterjetWelding | - |
| NMB Manufacturing LLC Milling, Turning, Bending, Welding | Bixby, OK | MillingTurningBendingWelding | - |
| Nocturnal Welding Welding | Camarillo, CA | Welding | - |
| Northern States Metals Bending, Welding, Stamping · ISO 9001 | Youngstown, OH | BendingWeldingStamping | ISO 9001 |
| Northlake Steel Corp Turning, Forging, Grinding, Finishing | Valley City, OH | TurningForgingGrindingFinishing | - |
| Northwest Steel Fab, Inc Milling, Punching, Bending, Welding | Deer Park, WA | MillingPunchingBendingWelding | - |