| Machine Time Inc Milling, Turning, Bending, Welding · ISO 9001, AS9100 | Nicholasville, KY | MillingTurningBendingWelding | ISO 9001, AS9100 |
| Machine Tool Services Turning, Bending, EDM | Spokane, WA | TurningBendingEDM | - |
| Magnum Steel Works Milling, Turning, Waterjet, Bending, Welding | Mount Vernon, IL | MillingTurningWaterjetBendingWelding | - |
| Make + SHift atx Bending | Austin, TX | Bending | - |
| Manor Tool & Manufacturing Co Milling, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001, ITAR | Schiller Park, IL | MillingLaserWaterjetBendingWeldingStampingEDMGrindingFinishing | ISO 9001, ITAR |
| Mark One Metal Works Turning, Bending, Welding | Sparks, NV | TurningBendingWelding | - |
| Massie Mfg Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Finishing · ITAR | Baraga, MI | MillingTurningLaserWaterjetBendingWeldingFinishing | ITAR |
| Master Metal Products Co Bending, Welding | San Jose, CA | BendingWelding | - |
| Matern Metal Works, Inc Punching, Bending, Welding | Mansfield, OH | PunchingBendingWelding | - |
| Max Machining LLC Milling, Turning, Laser, Bending · ITAR, CMMC | Telford, PA | MillingTurningLaserBending | ITAR, CMMC |
| Maynard Inc Bending, Welding · ISO 9001, AS9100, ITAR, NADCAP | Fayetteville, AR | BendingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| McKenna Metal Bending, Laser, Welding, Waterjet | Portland, OR | BendingLaserWeldingWaterjet | - |
| Mecha Inc Milling, Bending, Welding, Waterjet · ISO 9001, ITAR, NADCAP | Raleigh, NC | MillingBendingWeldingWaterjet | ISO 9001, ITAR, NADCAP |
| Melting Point Metalworks LLC Laser, Bending, Welding | Brownsburg, IN | LaserBendingWelding | - |
| Menze Precision Machining, LLC Milling, Turning, Bending, Welding, EDM, Grinding, Finishing | Winter Haven, FL | MillingTurningBendingWeldingEDMGrindingFinishing | - |
| Mercury Aircraft Inc Milling, Laser, Punching, Bending, Welding, Stamping, Assembly · ISO 9001, AS9100, ITAR | Hammondsport, NY | MillingLaserPunchingBendingWeldingStampingAssembly | ISO 9001, AS9100, ITAR |
| Metal Fabricators Plus LLC Laser, Waterjet, Bending, Welding | Indianapolis, IN | LaserWaterjetBendingWelding | - |
| Metal Man Milling, Waterjet, Bending, Welding | Watertown, NY | MillingWaterjetBendingWelding | - |
| Metal Masterminds Laser, Waterjet, Punching, Bending, Welding, Stamping | Fountain Valley, CA | LaserWaterjetPunchingBendingWeldingStamping | - |
| Metaltech CNC Machining LLC Milling, Turning, Bending | Portsmouth, RI | MillingTurningBending | - |
| Metaltech Inc Laser, Bending, Welding, Assembly · AS9100 | Auburn, WA | LaserBendingWeldingAssembly | AS9100 |
| Metalworking Group Bending, Welding · CMMC, ISO 9001, ITAR | Cincinnati, OH | BendingWelding | CMMC, ISO 9001, ITAR |
| 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 |
| MFC Netform LLC Milling, Laser, Waterjet, Bending, Welding, Stamping, Forging, EDM, Grinding · ISO 9001, IATF 16949 | Shelby Township, MI | MillingLaserWaterjetBendingWeldingStampingForgingEDMGrinding | ISO 9001, IATF 16949 |
| Microform Precision LLC Turning, Bending, Laser, Welding, Waterjet | Sacramento, CA | TurningBendingLaserWeldingWaterjet | - |
| Mid America Steel Inc Milling, Bending, Welding, Casting | Fargo, ND | MillingBendingWeldingCasting | - |
| Mid-Continent Engineering, LLC Bending, Welding, Grinding, Finishing · ISO 9001, AS9100, ITAR | Minneapolis, MN | BendingWeldingGrindingFinishing | ISO 9001, AS9100, ITAR |
| Mid-State Metals Bending, Welding | Orlando, FL | BendingWelding | - |
| Midlake Products & Mfg. Co., Inc Turning, Bending, Laser, Welding, Stamping | Canton, OH | TurningBendingLaserWeldingStamping | - |
| Midwest Industrial Metal Fabrication Inc Milling, Turning, Punching, Bending, Welding, Stamping, Finishing | Huntington, IN | MillingTurningPunchingBendingWeldingStampingFinishing | - |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| 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 | - |
| Mojo Masters LLC Milling, Laser, Bending, EDM, Grinding | Vestal, NY | MillingLaserBendingEDMGrinding | - |
| Moultrie Tool & Manufacturing Co Inc Milling, Turning, Bending, Welding, EDM, Stamping · ISO 9001 | Memphis, TN | MillingTurningBendingWeldingEDMStamping | ISO 9001 |
| 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 | - |
| Napoleon Machine LLC Milling, Bending, Welding, Forging, Grinding · ISO 9001, ITAR, CMMC | Napoleon, OH | MillingBendingWeldingForgingGrinding | ISO 9001, ITAR, CMMC |
| Netzer Metalworks, LLC Milling, Punching, Bending, Welding, Finishing, Assembly · NADCAP | Essex, MD | MillingPunchingBendingWeldingFinishingAssembly | NADCAP |
| New Method Steel Stamps Inc Milling, Turning, Laser, Bending, Stamping · ISO 9001 | Fraser, MI | MillingTurningLaserBendingStamping | ISO 9001 |
| Niagara Frontier Custom Fabrication Bending, Welding | Buffalo, NY | BendingWelding | - |
| Niagara Manufacturing Co Milling, Turning, Bending, Welding | Erie, PA | MillingTurningBendingWelding | - |
| NMB Manufacturing LLC Milling, Turning, Bending, Welding | Bixby, OK | MillingTurningBendingWelding | - |
| NRL & Associates Inc Milling, Turning, Bending, Welding, Assembly | Stevensville, MD | MillingTurningBendingWeldingAssembly | - |
| NW4S Inc Milling, Punching, Bending, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Lewiston, ID | MillingPunchingBendingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| Omega Metals Bending, Welding | Ogden, UT | BendingWelding | - |