| Miller CNC Milling, Turning, Welding, Grinding · ISO 9001, AS9100 | Chula Vista, CA | MillingTurningWeldingGrinding | ISO 9001, AS9100 |
| Milo Engineering Milling, Turning, Grinding, Finishing · ISO 9001 | Torrance, CA | MillingTurningGrindingFinishing | ISO 9001 |
| Miramar Metal Processing Inc Welding, Finishing · ITAR, NADCAP | San Diego, CA | WeldingFinishing | ITAR, NADCAP |
| MMG Corp Milling, Turning, Finishing, Assembly · ISO 9001 | Ontario, CA | MillingTurningFinishingAssembly | ISO 9001 |
| Modus Advanced Milling, Waterjet, Finishing, Assembly · ISO 9001, AS9100, ITAR, CMMC | Carlsbad, CA | MillingWaterjetFinishingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Mono Engineering Corp Turning, Welding, EDM · ISO 9001 | Chatsworth, CA | TurningWeldingEDM | ISO 9001 |
| National Metal Stampings - Temecula Valley Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Lancaster, CA | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Neff Engineering LLC Milling, Laser, Welding | Los Angeles, CA | MillingLaserWelding | - |
| Nelgo Manufacturing Co Milling, Turning, Punching, Welding · ISO 9001, AS9100, ITAR | Oceanside, CA | MillingTurningPunchingWelding | ISO 9001, AS9100, ITAR |
| Next Intent, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, ITAR | San Luis Obispo, CA | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, ITAR |
| Nexus Automation Milling, Welding, EDM, Assembly · ISO 9001, ITAR, ISO 13485 | Livermore, CA | MillingWeldingEDMAssembly | ISO 9001, ITAR, ISO 13485 |
| O & Y Precision Inc Milling, Laser, Waterjet, Bending, Welding, EDM, Finishing, Assembly | Morgan Hill, CA | MillingLaserWaterjetBendingWeldingEDMFinishingAssembly | - |
| Olson & Co. Steel Welding | Fresno, CA | Welding | - |
| Omanson Precision Engineering, Inc Milling, Finishing · ISO 9001, AS9100 | Chino, CA | MillingFinishing | ISO 9001, AS9100 |
| Pacific Maritime Industries Corp Milling, Turning, Laser, Waterjet, Punching, Bending, Welding · ISO 9001 | San Diego, CA | MillingTurningLaserWaterjetPunchingBendingWelding | ISO 9001 |
| Parallax Manufacturing LLC Milling, Turning, Bending, Welding, Stamping, Assembly · NADCAP | Lake Elsinore, CA | MillingTurningBendingWeldingStampingAssembly | NADCAP |
| PCL, LLC Milling, Turning, Swiss, Finishing · NADCAP | Oxnard, CA | MillingTurningSwissFinishing | NADCAP |
| Pegasus Machining Solutions Milling, Turning, Finishing | San Jose, CA | MillingTurningFinishing | - |
| Perforated Panels Laser, Waterjet, Bending, Welding | Pacoima, CA | LaserWaterjetBendingWelding | - |
| Peridot Corp Laser, Welding | Pleasanton, CA | LaserWelding | - |
| Pervan Industries Milling, Turning, Waterjet, Punching, Bending · ISO 9001, AS9100 | Compton, CA | MillingTurningWaterjetPunchingBending | ISO 9001, AS9100 |
| Petersen Precision Engineering LLC Milling, Turning, Swiss, EDM, Grinding, Finishing · ISO 9001, AS9100, ISO 13485 | Redwood City, CA | MillingTurningSwissEDMGrindingFinishing | ISO 9001, AS9100, ISO 13485 |
| Pimtad Aerospace LLC Milling, Turning, Swiss, Welding, Grinding, Assembly · AS9100 | Valencia, CA | MillingTurningSwissWeldingGrindingAssembly | AS9100 |
| Pleasanton Tool & Manufacturing Inc Milling, Turning, Welding, EDM · ITAR | Pleasanton, CA | MillingTurningWeldingEDM | ITAR |
| Precision Machining & Fab Milling, Turning, Bending, Laser, Welding, Waterjet · ISO 9001, AS9100, ITAR | Anaheim, CA | MillingTurningBendingLaserWeldingWaterjet | ISO 9001, AS9100, ITAR |
| Premier Steel Bending, Welding | Anaheim, CA | BendingWelding | - |
| Prisecter Aerospace and Defense LLC Milling, Turning, Waterjet, Welding, Assembly · AS9100, ITAR, CMMC | Auburn, CA | MillingTurningWaterjetWeldingAssembly | AS9100, ITAR, CMMC |
| Pro-Tek Manufacturing Inc Bending, Welding | Livermore, CA | BendingWelding | - |
| Process Stainless Lab Welding, Finishing, Assembly · ISO 9001 | Milpitas, CA | WeldingFinishingAssembly | ISO 9001 |
| Proto Solutions and Machining Turning, Welding, Assembly | San Diego, CA | TurningWeldingAssembly | - |
| Protool Co Milling, Turning, Swiss · ISO 9001 | Tustin, CA | MillingTurningSwiss | ISO 9001 |
| Prototek Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting, Metal AM · ISO 9001, AS9100, ITAR, CMMC | Rancho Cordova, CA | MillingTurningBendingLaserWeldingWaterjetEDMCastingMetal AM | ISO 9001, AS9100, ITAR, CMMC |
| PTG Precision LLC Milling, Turning, Swiss, Welding, Grinding, Assembly · ISO 9001, AS9100, ITAR, CMMC | Gardena, CA | MillingTurningSwissWeldingGrindingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Quality Grinding Co, Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100 | Buena Park, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100 |
| Quantum Machining & Design Inc. Bending, Laser, Welding | Fresno, CA | BendingLaserWelding | - |
| R.M. Baker Machine & Tool, Inc Milling, Welding, EDM, Grinding, Finishing | Covina, CA | MillingWeldingEDMGrindingFinishing | - |
| Rache Corp Laser, Welding · ISO 9001, AS9100, ITAR | Camarillo, CA | LaserWelding | ISO 9001, AS9100, ITAR |
| Radian Thermal Products, Inc Milling, Casting, Finishing · ISO 9001, ITAR | Santa Clara, CA | MillingCastingFinishing | ISO 9001, ITAR |
| Radical Fabrications LLC Milling, Turning, Welding, Grinding | Lancaster, CA | MillingTurningWeldingGrinding | - |
| Rah Industries Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100, NADCAP | Santa Clarita, CA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100, NADCAP |
| Ram Aerospace Inc Milling, Turning, Laser, Waterjet, EDM, Grinding, Assembly · AS9100, ITAR | Brea, CA | MillingTurningLaserWaterjetEDMGrindingAssembly | AS9100, ITAR |
| Ramda Metal Specialities Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping · ISO 9001 | Gardena, CA | MillingTurningLaserWaterjetPunchingBendingWeldingStamping | ISO 9001 |
| Ramp Engineering Inc Milling, Turning, Swiss | Paramount, CA | MillingTurningSwiss | - |
| RBH Aerospace Inc Milling, Turning, Waterjet, Bending | Lakewood, CA | MillingTurningWaterjetBending | - |
| Rieker Machine LLC Welding, Assembly | Carlsbad, CA | WeldingAssembly | - |
| Rincon Engineering Corporation Milling, Turning, Laser, Waterjet, Punching, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Carpinteria, CA | MillingTurningLaserWaterjetPunchingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| Roller Technologies Co Milling, Turning, Welding, Finishing, Assembly | Upland, CA | MillingTurningWeldingFinishingAssembly | - |
| Royal Coatings Grinding, Finishing | Simi Valley, CA | GrindingFinishing | - |
| S & S Commercial Fishing Equipment, Incorporated Milling, Turning, Welding | Roseville, CA | MillingTurningWelding | - |
| S R Machining, Inc Milling, Turning, Swiss, Welding, Casting · ISO 9001, AS9100 | Norco, CA | MillingTurningSwissWeldingCasting | ISO 9001, AS9100 |