| Novo Modo Machining Milling · ISO 9001, AS9100, ITAR, CMMC | Mount Vernon, WA | Milling | ISO 9001, AS9100, ITAR, CMMC |
| NRL & Associates Inc Milling, Turning, Bending, Welding, Assembly | Stevensville, MD | MillingTurningBendingWeldingAssembly | - |
| NS Precision, Inc Milling, Finishing, Assembly · ITAR | Cornelius, NC | MillingFinishingAssembly | ITAR |
| Numerical Precision Inc Milling, Turning, Welding, EDM | Crosby, TX | MillingTurningWeldingEDM | - |
| Numericraft, Inc Milling, Turning, Finishing, Assembly | Tucson, AZ | MillingTurningFinishingAssembly | - |
| Nusource, LLC Welding, Assembly | Alexandria, VA | WeldingAssembly | - |
| NW4S Inc Milling, Punching, Bending, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Lewiston, ID | MillingPunchingBendingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| O'Connell Machinery Co Inc Milling, Welding | Buffalo, NY | MillingWelding | - |
| Oak Ridge Tool-Engineering Inc Milling, Turning, Welding, EDM, Grinding | Oak Ridge, TN | MillingTurningWeldingEDMGrinding | - |
| Odat Machine Milling, Turning, Welding, Grinding | Gorham, ME | MillingTurningWeldingGrinding | - |
| Ofallon Casting LLC Casting, EDM | O Fallon, MO | CastingEDM | - |
| Olson & Co. Steel Welding | Fresno, CA | Welding | - |
| 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 |
| Olympus Machining Milling, Turning · ITAR, CMMC | Hanover, PA | MillingTurning | ITAR, CMMC |
| Omikron Engineering, Inc Milling, Turning, Swiss, Assembly · ISO 9001 | Chatsworth, CA | MillingTurningSwissAssembly | ISO 9001 |
| Onium Machine and Fabrication, LLC Milling, Turning, Laser, Bending, Welding, Assembly · ISO 9001 | Winder, GA | MillingTurningLaserBendingWeldingAssembly | ISO 9001 |
| 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 |
| Orbel Corp Stamping, Finishing | Easton, PA | StampingFinishing | - |
| Oregon Screw Machine Products Milling, Turning | Portland, OR | MillingTurning | - |
| Origin Manufacturing LLC Milling | Newport, RI | Milling | - |
| Outback Manufacturing Milling, Turning, Swiss · AS9100, ITAR | Bend, OR | MillingTurningSwiss | AS9100, ITAR |
| Pacon Mfg, Inc Milling, Turning, Welding, Finishing · ISO 9001 | Livermore, CA | MillingTurningWeldingFinishing | ISO 9001 |
| Padgett Machine Tools Co Inc Milling, Turning, Stamping, Finishing · AS9100 | Gatesville, TX | MillingTurningStampingFinishing | AS9100 |
| Paligen Technologies Welding, Forging | Garland, TX | WeldingForging | - |
| Palma Acquisition Inc Milling, Turning, EDM, Grinding · ISO 9001, AS9100, ITAR | Lancaster, NY | MillingTurningEDMGrinding | ISO 9001, AS9100, ITAR |
| Parallax Manufacturing LLC Milling, Turning, Bending, Welding, Stamping, Assembly · NADCAP | Lake Elsinore, CA | MillingTurningBendingWeldingStampingAssembly | NADCAP |
| Paramount Machine Milling, Turning, EDM · ISO 9001, AS9100, ITAR | Salt Lake City, UT | MillingTurningEDM | ISO 9001, AS9100, ITAR |
| Partco, LLC Turning, Welding | Port Allen, LA | TurningWelding | - |
| Patterson Precision Manufacturing Inc Milling, Turning, Stamping, Grinding · ISO 9001, NADCAP | Norton Shores, MI | MillingTurningStampingGrinding | ISO 9001, NADCAP |
| PBZ Manufacturing Laser, Bending, Welding, Finishing · ISO 9001 | Lititz, PA | LaserBendingWeldingFinishing | ISO 9001 |
| Pcdrilling LLC Milling · ITAR | Tempe, AZ | Milling | ITAR |
| PDS Milling, Turning, Swiss, Finishing, Assembly · ISO 9001 | Minneapolis, MN | MillingTurningSwissFinishingAssembly | ISO 9001 |
| Peerless Precision Inc Milling, Turning, Welding, Grinding · ISO 9001, AS9100, ITAR | Westfield, MA | MillingTurningWeldingGrinding | ISO 9001, AS9100, ITAR |
| Pegasus Mfg Inc Milling, Turning, Metal AM · ISO 9001, AS9100 | Galesburg, IL | MillingTurningMetal AM | ISO 9001, AS9100 |
| Pen Manufacturing Milling, Turning, Bending, Welding · ISO 9001, AS9100, ITAR, NADCAP | Anaheim, CA | MillingTurningBendingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| Peninsula Precision Machine LLC Milling, Turning, Bending, Finishing | Deland, FL | MillingTurningBendingFinishing | - |
| Pennsylvania Steel Co. Inc. Welding · ISO 9001 | Birmingham, AL | Welding | ISO 9001 |
| Perma-Brass, Inc Milling, Turning, Swiss, Finishing · ISO 9001, AS9100 | Plymouth, WI | MillingTurningSwissFinishing | ISO 9001, AS9100 |
| Perseo-Erie Machine Sales Milling, Laser, EDM, Stamping | Erie, PA | MillingLaserEDMStamping | - |
| Petersen Precision Engineering LLC Milling, Turning, Swiss, EDM, Grinding, Finishing · ISO 9001, AS9100, ISO 13485 | Redwood City, CA | MillingTurningSwissEDMGrindingFinishing | ISO 9001, AS9100, ISO 13485 |
| Petit Tool Company Milling, Turning, Punching, Welding, Stamping, Grinding · ISO 9001, ITAR | Thomaston, CT | MillingTurningPunchingWeldingStampingGrinding | ISO 9001, ITAR |
| Pga Machine Co Milling, Turning, Waterjet, Welding, Finishing | Eddystone, PA | MillingTurningWaterjetWeldingFinishing | - |
| PGI Milling, Turning, Bending, Laser, Welding, Waterjet, EDM · AS9100, ITAR | Albuquerque, NM | MillingTurningBendingLaserWeldingWaterjetEDM | AS9100, ITAR |
| Piccolo Precision Products Inc Milling, Turning, Swiss | Madison Lake, MN | MillingTurningSwiss | - |
| Pioneer Products, Inc Milling, Turning, Casting, Grinding, Finishing, Assembly | Racine, WI | MillingTurningCastingGrindingFinishingAssembly | - |
| Pittsburgh Precision Turned Products, LLC Milling, Turning, Grinding, Finishing, Assembly · ISO 9001 | Pittsburgh, PA | MillingTurningGrindingFinishingAssembly | ISO 9001 |
| Pivotal Manufacturing Inc Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001 | Braham, MN | MillingTurningLaserBendingWeldingFinishing | ISO 9001 |
| PL Machine Corporation Milling, Turning, Bending, Finishing · ISO 9001 | Los Alamitos, CA | MillingTurningBendingFinishing | ISO 9001 |
| Plasidyne Engineering & Manufacturing Milling, Turning · ISO 9001, AS9100, ITAR | Long Beach, CA | MillingTurning | ISO 9001, AS9100, ITAR |