| Martin's Metal Fabrication & Welding, Inc Milling, Turning, Laser, Waterjet, Bending, Welding | Vacaville, CA | MillingTurningLaserWaterjetBendingWelding | - |
| 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 | - |
| Master Tool & Manufacturing Inc Turning, Bending, Welding, EDM, Grinding · ISO 9001, ITAR | Hiawatha, IA | TurningBendingWeldingEDMGrinding | ISO 9001, ITAR |
| Matern Metal Works, Inc Punching, Bending, Welding | Mansfield, OH | PunchingBendingWelding | - |
| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| Maynard Inc Bending, Welding · ISO 9001, AS9100, ITAR, NADCAP | Fayetteville, AR | BendingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| McAlpin Industries Inc. Milling, Bending, Laser, Welding, Stamping | Rochester, NY | MillingBendingLaserWeldingStamping | - |
| McKenna Metal Bending, Laser, Welding, Waterjet | Portland, OR | BendingLaserWeldingWaterjet | - |
| McKiney Manufacturing Milling, Turning, Laser, Waterjet, Bending, Welding | Mitchell, NE | MillingTurningLaserWaterjetBendingWelding | - |
| MCW Certified Welding Ltd Punching, Bending, Welding | Delta, OH | PunchingBendingWelding | - |
| Mecha Inc Milling, Bending, Welding, Waterjet · ISO 9001, ITAR, NADCAP | Raleigh, NC | MillingBendingWeldingWaterjet | ISO 9001, ITAR, NADCAP |
| Megla Manufacturing, Inc. Milling, Bending, Laser, Welding, Waterjet | National City, CA | MillingBendingLaserWeldingWaterjet | - |
| Melton Sheet Metal Bending, Welding | Fresno, CA | BendingWelding | - |
| 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 |
| Merritt Welding & Fabrication Bending, Welding | Denver, CO | BendingWelding | - |
| 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 Fabricators Plus LLC Laser, Waterjet, Bending, Welding | Indianapolis, IN | LaserWaterjetBendingWelding | - |
| Metal Line Bending, Welding | Salt Lake City, UT | BendingWelding | - |
| Metal Man Milling, Waterjet, Bending, Welding | Watertown, NY | MillingWaterjetBendingWelding | - |
| Metal Masterminds Laser, Waterjet, Punching, Bending, Welding, Stamping | Fountain Valley, CA | LaserWaterjetPunchingBendingWeldingStamping | - |
| Metal Pro, Inc. Milling, Bending, Welding | Phoenix, AZ | MillingBendingWelding | - |
| Metal Products Inc Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding | Appleton, WI | MillingTurningWaterjetBendingWeldingEDMGrinding | - |
| Metal Workz L.L.C Milling, Turning, Laser, Bending, Welding, Finishing | Albany, KY | MillingTurningLaserBendingWeldingFinishing | - |
| Metalcraft Creative Bending, Laser, Welding | Birmingham, AL | BendingLaserWelding | - |
| Metalcraft Inc Bending, Laser, Welding | Boise, ID | BendingLaserWelding | - |
| Metalcraft Services Of Tampa, LLC. Bending, Welding, Waterjet, Stamping | Tampa, FL | BendingWeldingWaterjetStamping | - |
| MetalMania Bending, Laser, Welding | Brooklyn, NY | BendingLaserWelding | - |
| Metaltech Inc Laser, Bending, Welding, Assembly · AS9100 | Auburn, WA | LaserBendingWeldingAssembly | AS9100 |
| MetalWork Austin Bending, Welding | Austin, TX | BendingWelding | - |
| Metalworking Group Bending, Welding · CMMC, ISO 9001, ITAR | Cincinnati, OH | BendingWelding | CMMC, ISO 9001, ITAR |
| Metco Metal Fab. Bending, Laser, Welding | Chattanooga, TN | BendingLaserWelding | - |
| MFC Netform LLC Milling, Laser, Waterjet, Bending, Welding, Stamping, Forging, EDM, Grinding · ISO 9001, IATF 16949 | Shelby Township, MI | MillingLaserWaterjetBendingWeldingStampingForgingEDMGrinding | ISO 9001, IATF 16949 |
| Micro Metals Inc Milling, Laser, Waterjet, Punching, Bending, Welding | Colorado Springs, CO | MillingLaserWaterjetPunchingBendingWelding | - |
| 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 Metal Fabrications Milling, Turning, Bending, Laser, Welding · ISO 9001, AS9100 | Tallmadge, OH | MillingTurningBendingLaserWelding | ISO 9001, AS9100 |
| 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 |
| Millwood Metalworks Punching, Bending, Welding | Freeport, MN | PunchingBendingWelding | - |
| Milton Manufacturing, Inc Turning, Bending, Welding, Stamping, Assembly · ITAR | Detroit, MI | TurningBendingWeldingStampingAssembly | ITAR |
| 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 |