| Marion Precision Tool, Inc Milling, Turning, Waterjet, Bending, Welding, Grinding · ISO 9001 | Ocala, FL | MillingTurningWaterjetBendingWeldingGrinding | ISO 9001 |
| Mark One Metal Works Turning, Bending, Welding | Sparks, NV | TurningBendingWelding | - |
| Marsan Inc Bending, Welding, Assembly · ISO 9001 | Germantown, WI | BendingWeldingAssembly | ISO 9001 |
| Martin's Metal Fabrication & Welding, Inc Milling, Turning, Laser, Waterjet, Bending, Welding | Vacaville, CA | MillingTurningLaserWaterjetBendingWelding | - |
| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| McAlpin Industries Inc. Milling, Bending, Laser, Welding, Stamping | Rochester, NY | MillingBendingLaserWeldingStamping | - |
| 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 |
| 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 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 Workz L.L.C Milling, Turning, Laser, Bending, Welding, Finishing | Albany, KY | MillingTurningLaserBendingWeldingFinishing | - |
| MetalMania Bending, Laser, Welding | Brooklyn, NY | BendingLaserWelding | - |
| Metalmasters Milling, Turning, Bending, Welding, Finishing | Brighton, CO | MillingTurningBendingWeldingFinishing | - |
| Metaltech Inc Laser, Bending, Welding, Assembly · AS9100 | Auburn, WA | LaserBendingWeldingAssembly | AS9100 |
| MetalWork Austin Bending, Welding | Austin, TX | BendingWelding | - |
| 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 |
| 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 | - |
| Midwest Metal Fabrications Milling, Turning, Bending, Laser, Welding · ISO 9001, AS9100 | Tallmadge, OH | MillingTurningBendingLaserWelding | ISO 9001, AS9100 |
| 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 | - |
| Milwaukee Metal Products Co Bending, Welding, Stamping | Milwaukee, WI | BendingWeldingStamping | - |
| MJM Manufacturing Inc Milling, Laser, Punching, Bending, Welding, Stamping · ISO 9001, AS9100, ITAR | Miami Lakes, FL | MillingLaserPunchingBendingWeldingStamping | ISO 9001, AS9100, ITAR |
| Mofab Inc Milling, Laser, Waterjet, Bending, Welding | Anderson, IN | MillingLaserWaterjetBendingWelding | - |
| Morrison Industries LLC Milling, Turning, Laser, Bending, Welding, Finishing, Assembly | Morrison, TN | MillingTurningLaserBendingWeldingFinishingAssembly | - |
| 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 | - |
| Nace Sheet Metal Co Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| Naimor Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly | Snohomish, WA | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | - |
| 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 |
| Nevada Precision Sheet Metal Milling, Bending, Laser, Welding, Waterjet | Las Vegas, NV | MillingBendingLaserWeldingWaterjet | - |
| 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 |
| Niagara Frontier Custom Fabrication Bending, Welding | Buffalo, NY | BendingWelding | - |
| Niagara Manufacturing Co Milling, Turning, Bending, Welding | Erie, PA | MillingTurningBendingWelding | - |
| Northern States Metals Bending, Welding, Stamping · ISO 9001 | Youngstown, OH | BendingWeldingStamping | ISO 9001 |
| Northway Mathers Inc Milling, Turning, Waterjet, Bending, Welding, Finishing | Mukilteo, WA | MillingTurningWaterjetBendingWeldingFinishing | - |
| Northwest Steel Fab, Inc Milling, Punching, Bending, Welding | Deer Park, WA | MillingPunchingBendingWelding | - |
| NW4S Inc Milling, Punching, Bending, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Lewiston, ID | MillingPunchingBendingWeldingStampingEDMFinishing | ISO 9001, AS9100 |