| 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 |
| Moria Manufacturing LLC Milling, Turning, Finishing | Monona, WI | MillingTurningFinishing | - |
| Morrison Industries LLC Milling, Turning, Laser, Bending, Welding, Finishing, Assembly | Morrison, TN | MillingTurningLaserBendingWeldingFinishingAssembly | - |
| Motive Machine Works LLC Milling, Turning, Stamping, Finishing, Assembly | Lancaster, PA | MillingTurningStampingFinishingAssembly | - |
| Mountain CNC Milling, Turning, Waterjet, Welding, Grinding, Finishing, Assembly · ITAR, CMMC | Loveland, CO | MillingTurningWaterjetWeldingGrindingFinishingAssembly | ITAR, CMMC |
| Mountain Defense LLC Milling, Turning, EDM, Assembly | Mentor, OH | MillingTurningEDMAssembly | - |
| 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 | - |
| Multi-Machining Co Inc Milling, Turning, Finishing, Assembly | Greenville, TX | MillingTurningFinishingAssembly | - |
| Multiplex Machining Milling, Turning · AS9100 | Houston, TX | MillingTurning | AS9100 |
| Multisource Manufacturing LLC Milling, Turning, Swiss, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | Minneapolis, MN | MillingTurningSwissEDMGrindingFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |
| 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 | - |
| Naimor Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly | Snohomish, WA | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | - |
| National Metal Stampings - Temecula Valley Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Lancaster, CA | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Natoma Manufacturing, LLC Milling, Turning, Swiss, Finishing · ISO 9001, AS9100, NADCAP | Norton, KS | MillingTurningSwissFinishing | ISO 9001, AS9100, NADCAP |
| Nebraska Machine Products, Inc Turning, Welding, Grinding, Finishing | Omaha, NE | TurningWeldingGrindingFinishing | - |
| New Age Manufacturing, Inc Milling, Turning, Welding, Grinding, Finishing, Assembly · ISO 9001 | Plattsmouth, NE | MillingTurningWeldingGrindingFinishingAssembly | 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 |
| Niagara Manufacturing Co Milling, Turning, Bending, Welding | Erie, PA | MillingTurningBendingWelding | - |
| Nix Manufacturing, Inc Milling, Turning, Swiss · AS9100, ITAR | Sutherlin, OR | MillingTurningSwiss | AS9100, ITAR |
| Nominal Machining LLC Milling, Turning, Welding · ISO 9001, AS9100, ITAR | Elk Grove, CA | MillingTurningWelding | ISO 9001, AS9100, ITAR |
| Noron Precision Machining Inc Milling, Turning, Grinding, Finishing, Assembly · ISO 9001, ITAR | Sunnyvale, CA | MillingTurningGrindingFinishingAssembly | ISO 9001, 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 East Precision CNC Milling, Turning · ISO 9001, ITAR | Dover, NH | MillingTurning | ISO 9001, ITAR |
| North Easton Machine Company, Inc Milling, Turning, Swiss · ISO 9001, ITAR, CMMC | North Easton, MA | MillingTurningSwiss | ISO 9001, ITAR, CMMC |
| Northeast Manufacturing Milling, Turning, Assembly · ISO 9001 | Stoneham, MA | MillingTurningAssembly | ISO 9001 |
| Northeast Tool and Mfg. Co Milling, Turning, EDM · ISO 9001, AS9100, ITAR, CMMC | Matthews, NC | MillingTurningEDM | ISO 9001, AS9100, ITAR, CMMC |
| Northern Lucus Machine Shop Turning, Punching, Welding | Lubbock, TX | TurningPunchingWelding | - |
| Northern Machining & Repair, Inc Milling, Turning, Welding | Escanaba, MI | MillingTurningWelding | - |
| Northway Mathers Inc Milling, Turning, Waterjet, Bending, Welding, Finishing | Mukilteo, WA | MillingTurningWaterjetBendingWeldingFinishing | - |
| Nova Precision Products Inc Turning | Rockaway, NJ | Turning | - |
| NTO Designs Milling, Turning, Laser, Welding, Finishing | Ormond Beach, FL | MillingTurningLaserWeldingFinishing | - |
| Nu-Tech Machining Inc Milling, Turning · ITAR | Vancouver, WA | MillingTurning | ITAR |
| Numericraft, Inc Milling, Turning, Finishing, Assembly | Tucson, AZ | MillingTurningFinishingAssembly | - |
| O&R Precision Milling, Turning, Swiss, Stamping, EDM, Grinding · ISO 9001 | Berne, IN | MillingTurningSwissStampingEDMGrinding | ISO 9001 |
| Oak Ridge Tool-Engineering Inc Milling, Turning, Welding, EDM, Grinding | Oak Ridge, TN | MillingTurningWeldingEDMGrinding | - |
| Olympic Tool Company Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Finishing, Assembly | Bayville, NJ | MillingTurningWaterjetBendingWeldingEDMGrindingFinishingAssembly | - |
| Olympus Machining Milling, Turning · ITAR, CMMC | Hanover, PA | MillingTurning | ITAR, CMMC |
| Omega Precision Milling, Turning · ISO 9001 | Santa Fe Springs, CA | MillingTurning | ISO 9001 |
| Omni Machine Works Inc Milling, Turning, Welding, EDM, Grinding | Covington, GA | MillingTurningWeldingEDMGrinding | - |
| Omni Precision Components Milling, Turning, Finishing · ISO 9001 | Holland, MI | MillingTurningFinishing | ISO 9001 |
| OMS Precision Machining Milling, Turning, Swiss, Casting, Grinding, Finishing · ISO 9001, ITAR | Oshkosh, WI | MillingTurningSwissCastingGrindingFinishing | ISO 9001, ITAR |
| On Sh0re USA LLC Milling, Turning | Glendale Heights, IL | MillingTurning | - |
| Onamac Industries, Inc Milling, Turning, Casting, Grinding · ISO 9001, AS9100 | Everett, WA | MillingTurningCastingGrinding | ISO 9001, AS9100 |