| Miramar Metal Processing Inc Welding, Finishing · ITAR, NADCAP | San Diego, CA | WeldingFinishing | ITAR, NADCAP |
| Mirror Finish Polishing Welding, Casting, Grinding | Kearney, MO | WeldingCastingGrinding | - |
| MJM Manufacturing Inc Milling, Laser, Punching, Bending, Welding, Stamping · ISO 9001, AS9100, ITAR | Miami Lakes, FL | MillingLaserPunchingBendingWeldingStamping | ISO 9001, AS9100, ITAR |
| Modern Machine Works Milling, Turning, Welding, EDM, Grinding, Finishing | Albany, OR | MillingTurningWeldingEDMGrindingFinishing | - |
| Mofab Inc Milling, Laser, Waterjet, Bending, Welding | Anderson, IN | MillingLaserWaterjetBendingWelding | - |
| Mono Engineering Corp Turning, Welding, EDM · ISO 9001 | Chatsworth, CA | TurningWeldingEDM | ISO 9001 |
| Montgomery Dynamics Milling, Turning, Welding · ISO 9001, ITAR | Huntingdon Valley, PA | MillingTurningWelding | ISO 9001, ITAR |
| Morehead Machinery Inc Milling, Turning, Welding, EDM, Grinding | Elkhart, IN | MillingTurningWeldingEDMGrinding | - |
| Morgan Bronze Products, Inc Turning, Welding, Casting · ISO 9001 | Lake Zurich, IL | TurningWeldingCasting | ISO 9001 |
| Morrison Industries LLC Milling, Turning, Laser, Bending, Welding, Finishing, Assembly | Morrison, TN | MillingTurningLaserBendingWeldingFinishingAssembly | - |
| Mountain CNC Milling, Turning, Waterjet, Welding, Grinding, Finishing, Assembly · ITAR, CMMC | Loveland, CO | MillingTurningWaterjetWeldingGrindingFinishingAssembly | ITAR, CMMC |
| Mountain Precision Tool Co, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, EDM, Grinding, Finishing | Blacksburg, VA | MillingTurningLaserWaterjetPunchingBendingWeldingEDMGrindingFinishing | - |
| MPM, Inc Milling, Welding, EDM | Wichita, KS | MillingWeldingEDM | - |
| MSP Maufacturing Milling, Turning, Bending, Welding, Finishing, Assembly | Bloomington, IN | MillingTurningBendingWeldingFinishingAssembly | - |
| N & S Flame Spray, LLC Milling, Turning, Welding, Grinding | Mannford, OK | MillingTurningWeldingGrinding | - |
| N.C.T., Inc Milling, Turning, Swiss, Welding, Grinding | Colchester,, CT | MillingTurningSwissWeldingGrinding | - |
| N.e.t. & Die, Inc Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing | Fulton, NY | MillingTurningLaserWaterjetWeldingGrindingFinishing | - |
| 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 |
| Nassau Metal Works LLC Welding | Yulee, FL | Welding | - |
| National Metal Stampings - Temecula Valley Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Lancaster, CA | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Nebraska Machine Products, Inc Turning, Welding, Grinding, Finishing | Omaha, NE | TurningWeldingGrindingFinishing | - |
| 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 Age Manufacturing, Inc Milling, Turning, Welding, Grinding, Finishing, Assembly · ISO 9001 | Plattsmouth, NE | MillingTurningWeldingGrindingFinishingAssembly | ISO 9001 |
| 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 |
| Next Intent, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, ITAR | San Luis Obispo, CA | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, ITAR |
| Next Tech Manufacturing Inc Milling, Welding, Finishing | Santa Clara, CA | MillingWeldingFinishing | - |
| Niagara Frontier Custom Fabrication Bending, Welding | Buffalo, NY | BendingWelding | - |
| Niagara Manufacturing Co Milling, Turning, Bending, Welding | Erie, PA | MillingTurningBendingWelding | - |
| NJ Precision Technologies Inc Milling, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | Mountainside, NJ | MillingWeldingStampingEDMFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |
| Nominal Machining LLC Milling, Turning, Welding · ISO 9001, AS9100, ITAR | Elk Grove, CA | MillingTurningWelding | ISO 9001, AS9100, ITAR |
| Nortek, Inc Milling, Turning, Swiss, Laser, Waterjet, Welding, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR, NADCAP | West Springfield, MA | MillingTurningSwissLaserWaterjetWeldingEDMGrindingFinishing | ISO 9001, AS9100, ITAR, NADCAP |
| North Second Street Steel Laser, Welding | Minneapolis, MN | LaserWelding | - |
| Northern Lucus Machine Shop Turning, Punching, Welding | Lubbock, TX | TurningPunchingWelding | - |
| Northern Machining & Repair, Inc Milling, Turning, Welding | Escanaba, MI | MillingTurningWelding | - |
| 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 | - |
| NTO Designs Milling, Turning, Laser, Welding, Finishing | Ormond Beach, FL | MillingTurningLaserWeldingFinishing | - |
| NW4S Inc Milling, Punching, Bending, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Lewiston, ID | MillingPunchingBendingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| O. W. Landergren, Inc Milling, Laser, Punching, Bending, Welding, Stamping, EDM, Grinding, Finishing | Pittsfield, MA | MillingLaserPunchingBendingWeldingStampingEDMGrindingFinishing | - |
| Oak Ridge Tool-Engineering Inc Milling, Turning, Welding, EDM, Grinding | Oak Ridge, TN | MillingTurningWeldingEDMGrinding | - |
| Odin Fabrication, Inc Laser, Punching, Welding, Finishing | Elburn, IL | LaserPunchingWeldingFinishing | - |
| Olympic Industries Laser, Welding, Stamping | Cordova, TN | LaserWeldingStamping | - |
| Olympic Tool Company Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Finishing, Assembly | Bayville, NJ | MillingTurningWaterjetBendingWeldingEDMGrindingFinishingAssembly | - |
| Olympus Foundry Welding, Casting · AS9100, NADCAP | Millcreek, UT | WeldingCasting | AS9100, NADCAP |
| Omega Metals Bending, Welding | Ogden, UT | BendingWelding | - |