| PCL, LLC Milling, Turning, Swiss, Finishing · NADCAP | Oxnard, CA | MillingTurningSwissFinishing | NADCAP |
| PHD Machining LLC Milling, EDM, Assembly | Santa Clara, CA | MillingEDMAssembly | - |
| Raw Machining Co Milling | Buena Park, CA | Milling | - |
| TQ Systems Inc Milling, Turning, EDM, Assembly | Lake Forest, CA | MillingTurningEDMAssembly | - |
| Weldtec Manufacturing, Inc Welding | Waterford, CA | Welding | - |
| 3dcam International Corp Milling, Casting, Assembly | Chatsworth, CA | MillingCastingAssembly | - |
| A & A Fabrication and Polishing Corporation Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001, AS9100 | Montebello, CA | MillingTurningLaserPunchingBendingWelding | ISO 9001, AS9100 |
| A & M Engineering Inc Milling | Irwindale, CA | Milling | - |
| A Precision Machining Corp Milling · AS9100, ITAR, CMMC | Shingle Springs, CA | Milling | AS9100, ITAR, CMMC |
| A&k Manufacturing Inc Turning, Welding, Assembly | Sun Valley, CA | TurningWeldingAssembly | - |
| Abacorp CNC Machined Parts Milling, Turning, Laser, Welding · AS9100 | Moorpark, CA | MillingTurningLaserWelding | AS9100 |
| Abc Sheet Metal Laser, Waterjet, Punching, Bending, Welding · ISO 9001, AS9100 | Anaheim, CA | LaserWaterjetPunchingBendingWelding | ISO 9001, AS9100 |
| Above All CNC Inc Milling, Turning · ISO 9001, AS9100, ITAR | Goleta, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| Absolute Precision Machining, Inc. Turning, Welding · ISO 9001, AS9100 | Anaheim, CA | TurningWelding | ISO 9001, AS9100 |
| AC Manufacturing Milling, Turning, Welding | San Jose, CA | MillingTurningWelding | - |
| Acc Precision Inc Milling, Turning, Welding, Grinding | Oxnard, CA | MillingTurningWeldingGrinding | - |
| Accuturn Corp Milling, Turning, Swiss, Grinding · AS9100 | Moreno Valley, CA | MillingTurningSwissGrinding | AS9100 |
| Acosta Sheet Metal Manufacturing Bending | San Jose, CA | Bending | - |
| Advanced Ceramic Technology Grinding · ITAR | Orange, CA | Grinding | ITAR |
| Advanced Engineering & EDM, Inc Milling, Turning, Laser, Stamping, EDM, Grinding | Poway, CA | MillingTurningLaserStampingEDMGrinding | - |
| Advanced Fabrication Bending, Welding, Waterjet | Bakersfield, CA | BendingWeldingWaterjet | - |
| Advanced Fabrication Technology Laser, Punching, Welding, Finishing, Assembly · ISO 9001 | Hayward, CA | LaserPunchingWeldingFinishingAssembly | ISO 9001 |
| Advanced Precision Machining, LLC Milling, Turning, Laser, Waterjet, EDM, Assembly · AS9100, ITAR, CMMC | Costa Mesa, CA | MillingTurningLaserWaterjetEDMAssembly | AS9100, ITAR, CMMC |
| Advanced Thrtical Concepts Inc Milling, Turning, Swiss, Laser, Waterjet, Welding, Grinding, Finishing | Camarillo, CA | MillingTurningSwissLaserWaterjetWeldingGrindingFinishing | - |
| Aerospace Manufacturing Inc Welding, Assembly · AS9100 | Canyon Countrt, CA | WeldingAssembly | AS9100 |
| Aerotech Precision Machining, Inc Milling, Turning, Assembly · ISO 9001, AS9100 | Lancaster, CA | MillingTurningAssembly | ISO 9001, AS9100 |
| All Time Machine Inc Milling, Turning, Finishing · AS9100 | Ontario, CA | MillingTurningFinishing | AS9100 |
| Alltech Precision Manufacturing Milling, Turning, EDM | Valencia, CA | MillingTurningEDM | - |
| Amador Steel and Supply, LLC Milling, Punching, Bending, Welding | Jackson, CA | MillingPunchingBendingWelding | - |
| American Precision Tool & Engineering, Inc Milling, Turning, Swiss, Welding, Grinding, Finishing | Pacoima, CA | MillingTurningSwissWeldingGrindingFinishing | - |
| Amex Plating Inc Finishing | Santa Clara, CA | Finishing | - |
| AMS Manufacturing Welding, EDM, Finishing, Assembly | San Jose, CA | WeldingEDMFinishingAssembly | - |
| APV Manufacturing Milling, Waterjet, Bending, Welding, Grinding · NADCAP | Buena Park, CA | MillingWaterjetBendingWeldingGrinding | NADCAP |
| Avalon Mfg, Inc Milling · AS9100 | Compton, CA | Milling | AS9100 |
| Axton Robotics LLC Milling, Turning, Finishing | San Diego, CA | MillingTurningFinishing | - |
| Axxis Corp Milling, Turning, Swiss, Laser · ISO 9001, AS9100, ITAR, ISO 13485 | Perris, CA | MillingTurningSwissLaser | ISO 9001, AS9100, ITAR, ISO 13485 |
| Beam on Technology Corporation Laser, Assembly · ITAR | Santa Clara, CA | LaserAssembly | ITAR |
| Beltim & Associates, LLC Milling, Turning, Swiss, Waterjet, Stamping, Casting, EDM, Finishing · ISO 9001, ITAR, ISO 13485 | Pleasanton, CA | MillingTurningSwissWaterjetStampingCastingEDMFinishing | ISO 9001, ITAR, ISO 13485 |
| Benen Manufacturing LLC Milling, Turning, Welding, Finishing, Assembly · ISO 9001, ISO 13485 | San Jose, CA | MillingTurningWeldingFinishingAssembly | ISO 9001, ISO 13485 |
| Beyond Precision, LLC Milling, Turning · ISO 9001, AS9100 | Santa Ana, CA | MillingTurning | ISO 9001, AS9100 |
| BS Designs Inc Milling, Turning, Welding | Santee, CA | MillingTurningWelding | - |
| C & S Aerospace, Inc Milling, Turning, EDM | Fullerton, CA | MillingTurningEDM | - |
| C & W Manufacturing Milling, Turning, Welding, Grinding, Finishing · ISO 9001, ITAR, CMMC | Turlock, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, ITAR, CMMC |
| C F W Precision Metal Components Waterjet, Assembly · ISO 9001 | Grover Beach, CA | WaterjetAssembly | ISO 9001 |
| California Amforge Corp Welding, Forging · ISO 9001, AS9100, ITAR, NADCAP | Azusa, CA | WeldingForging | ISO 9001, AS9100, ITAR, NADCAP |
| California Lasers Inc Milling, Laser, Welding, EDM, Grinding | Simi Valley, CA | MillingLaserWeldingEDMGrinding | - |
| Calrod Engineering, LLC Milling, Turning, Welding · ISO 9001, AS9100, ITAR | Costa Mesa, CA | MillingTurningWelding | ISO 9001, AS9100, ITAR |
| Campbell Engineering Milling, Welding, EDM, Finishing, Assembly · ISO 9001, ITAR | Lake Forest, CA | MillingWeldingEDMFinishingAssembly | ISO 9001, ITAR |
| Carney Mfg LLC Milling | Beaumont, CA | Milling | - |
| Casco Machining Inc. Milling, Turning, Welding · ISO 9001 | San Jose, CA | MillingTurningWelding | ISO 9001 |