| Merritt Welding & Fabrication Bending, Welding | Denver, CO | BendingWelding | - |
| Metal Arts LLC Welding | Wichita, KS | Welding | - |
| Metal Line Bending, Welding | Salt Lake City, UT | BendingWelding | - |
| 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 | - |
| 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 | - |
| 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 America Steel Inc Milling, Bending, Welding, Casting | Fargo, ND | MillingBendingWeldingCasting | - |
| 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 |
| Midwest Steel Works Inc. Welding | Lincoln, NE | Welding | - |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| 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 | - |
| Modern Custom Fabrication Welding | Fresno, CA | Welding | - |
| Modern Machine Milling, Turning, Bending, Welding, Stamping | Seattle, WA | MillingTurningBendingWeldingStamping | - |
| Morena Welding Inc Welding | San Diego, CA | Welding | - |
| 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 | - |
| New World Machining Inc Milling, Turning, Welding | San Jose, CA | MillingTurningWelding | - |
| 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 | - |
| North Second Street Steel Laser, Welding | Minneapolis, MN | LaserWelding | - |
| Northern States Metals Bending, Welding, Stamping · ISO 9001 | Youngstown, OH | BendingWeldingStamping | ISO 9001 |
| O'Connell Machinery Co Inc Milling, Welding | Buffalo, NY | MillingWelding | - |
| OGS Industries Turning, Bending, Laser, Welding, Stamping · ISO 9001, AS9100, ITAR, IATF 16949 | Akron, OH | TurningBendingLaserWeldingStamping | ISO 9001, AS9100, ITAR, IATF 16949 |
| Ohio Metal Fabricating Inc Turning, Bending, Laser, Welding, Stamping · AS9100 | Dayton, OH | TurningBendingLaserWeldingStamping | AS9100 |
| Olson & Co. Steel Welding | Fresno, CA | Welding | - |
| 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 |
| Orange County Sheet Metal Shop Bending, Laser, Welding, Stamping | Anaheim, CA | BendingLaserWeldingStamping | - |
| Oscar's Custom Iron Works Welding | San Antonio, TX | Welding | - |
| Ottenweller Company, Inc. Bending, Laser, Welding · ISO 9001 | Fort Wayne, IN | BendingLaserWelding | ISO 9001 |
| Owens Industries, Inc. Milling, Turning, Welding, EDM, Casting, Metal AM · ISO 9001, AS9100 | Oak Creek, WI | MillingTurningWeldingEDMCastingMetal AM | ISO 9001, AS9100 |