| Machine Time Inc Milling, Turning, Bending, Welding · ISO 9001, AS9100 | Nicholasville, KY | MillingTurningBendingWelding | ISO 9001, AS9100 |
| Machined Products Co Turning, Welding · ISO 9001 | Lancaster, PA | TurningWelding | ISO 9001 |
| Madden Fabrication Milling, Welding | Portland, OR | MillingWelding | - |
| Majestic Metals by Fathom Manufacturing Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting, Metal AM · ISO 9001, AS9100, ITAR, ISO 13485 | Denver, CO | MillingTurningBendingLaserWeldingWaterjetEDMCastingMetal AM | ISO 9001, AS9100, ITAR, ISO 13485 |
| Major Tool & Machine Milling, Turning, Welding · ISO 9001, AS9100, NADCAP | Indianapolis, IN | MillingTurningWelding | ISO 9001, AS9100, NADCAP |
| Maria Custom Sheet Metal Bending, Welding | Englewood, CO | BendingWelding | - |
| Mark One Metal Works Turning, Bending, Welding | Sparks, NV | TurningBendingWelding | - |
| Master Metal Products Co Bending, Welding | San Jose, CA | BendingWelding | - |
| Mat-Tech Machining Milling, Turning, Welding | Milwaukee, WI | MillingTurningWelding | - |
| Maumee Valley Fabricators Turning, Welding | Toledo, OH | TurningWelding | - |
| McAlpin Industries Inc. Milling, Bending, Laser, Welding, Stamping | Rochester, NY | MillingBendingLaserWeldingStamping | - |
| 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 |
| Megla Manufacturing, Inc. Milling, Bending, Laser, Welding, Waterjet | National City, CA | MillingBendingLaserWeldingWaterjet | - |
| Metal Arts LLC Welding | Wichita, KS | Welding | - |
| Metal Pro, Inc. Milling, Bending, Welding | Phoenix, AZ | MillingBendingWelding | - |
| Metal Works Precision Machine and Tool, Inc Milling, Turning, Welding | Tucson, AZ | MillingTurningWelding | - |
| Metalcraft Creative Bending, Laser, Welding | Birmingham, AL | BendingLaserWelding | - |
| MetalMania Bending, Laser, Welding | Brooklyn, NY | BendingLaserWelding | - |
| Metals Fabrication Co Milling, Turning, Welding | Airway Heights, WA | MillingTurningWelding | - |
| 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 | - |
| Metzger Machine Co. Milling, Turning, Welding | Cincinnati, OH | MillingTurningWelding | - |
| Micar Fabrication Milling, Turning, Welding | Las Vegas, NV | MillingTurningWelding | - |
| Microform Precision LLC Turning, Bending, Laser, Welding, Waterjet | Sacramento, CA | TurningBendingLaserWeldingWaterjet | - |
| Mid-State Metals Bending, Welding | Orlando, FL | BendingWelding | - |
| Midlake Products & Mfg. Co., Inc Turning, Bending, Laser, Welding, Stamping | Canton, OH | TurningBendingLaserWeldingStamping | - |
| Midwest Metal Fabrications Milling, Turning, Bending, Laser, Welding · ISO 9001, AS9100 | Tallmadge, OH | MillingTurningBendingLaserWelding | ISO 9001, AS9100 |
| Midwest Precision Inc Bending, Laser, Welding, Waterjet · ISO 9001 | Tulsa, OK | BendingLaserWeldingWaterjet | ISO 9001 |
| Miller Diversified Machining Milling, Turning, Welding · ISO 9001, ITAR | Minneapolis, MN | MillingTurningWelding | ISO 9001, ITAR |
| Milwaukee Metal Products Co Bending, Welding, Stamping | Milwaukee, WI | BendingWeldingStamping | - |
| Moultrie Tool & Manufacturing Co Inc Milling, Turning, Bending, Welding, EDM, Stamping · ISO 9001 | Memphis, TN | MillingTurningBendingWeldingEDMStamping | ISO 9001 |
| Music City Sheet Metal Bending, Laser, Welding | Nashville, TN | BendingLaserWelding | - |
| Nace Sheet Metal Co Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| Nashville Sheet Metal Bending, Welding | Nashville, TN | BendingWelding | - |
| Neosource, Inc. Milling, Welding, Waterjet · ISO 9001, AS9100 | Tulsa, OK | MillingWeldingWaterjet | ISO 9001, AS9100 |
| Nevada Precision Sheet Metal Milling, Bending, Laser, Welding, Waterjet | Las Vegas, NV | MillingBendingLaserWeldingWaterjet | - |
| Niagara Frontier Custom Fabrication Bending, Welding | Buffalo, NY | BendingWelding | - |
| Niagara Manufacturing Co Milling, Turning, Bending, Welding | Erie, PA | MillingTurningBendingWelding | - |
| Nicholson Metal Fabricators Bending, Welding | Dallas, TX | BendingWelding | - |
| Ohio Metal Fabricating Inc Turning, Bending, Laser, Welding, Stamping · AS9100 | Dayton, OH | TurningBendingLaserWeldingStamping | AS9100 |
| Omega Metals Bending, Welding | Ogden, UT | BendingWelding | - |
| Optima Precision Milling, Turning, Bending, Welding, EDM, Metal AM · ISO 9001, AS9100, ISO 13485, NADCAP | San Jose, CA | MillingTurningBendingWeldingEDMMetal AM | ISO 9001, AS9100, ISO 13485, NADCAP |
| Owens Industries, Inc. Milling, Turning, Welding, EDM, Casting, Metal AM · ISO 9001, AS9100 | Oak Creek, WI | MillingTurningWeldingEDMCastingMetal AM | ISO 9001, AS9100 |
| Pacific Architectural Metals LLC Bending, Laser, Welding | Seattle, WA | BendingLaserWelding | - |
| Patience Metal Fab Turning, Bending, Welding | Brooklyn Center, MN | TurningBendingWelding | - |
| Peak Custom Fabrication Bending, Welding | Colorado Springs, CO | BendingWelding | - |
| Penn Sheet Metal Bending, Laser, Welding, Waterjet | Allentown, PA | BendingLaserWeldingWaterjet | - |
| Performance Aluminum Fabrication Milling, Bending, Laser, Welding, Waterjet | Houston, TX | MillingBendingLaserWeldingWaterjet | - |