| Acosta Sheet Metal Manufacturing Bending | San Jose, CA | Bending | - |
| Additive Plus Metal AM · AS9100, ITAR, NADCAP, ISO 13485 | Sherman Oaks, CA | Metal AM | AS9100, ITAR, NADCAP, ISO 13485 |
| Advance Virtu CNC Milling, Turning | Glendale, CA | MillingTurning | - |
| Advanced Ceramic Technology Grinding · ITAR | Orange, CA | Grinding | ITAR |
| Advanced Engineering & EDM, Inc Milling, Turning, Laser, Stamping, EDM, Grinding | Poway, CA | MillingTurningLaserStampingEDMGrinding | - |
| Advanced Metal Manufacturing Inc Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001, AS9100 | Simi Valley, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001, AS9100 |
| Advantage Metal Products, Inc Milling, Bending, Finishing, Assembly · ITAR | Livermore, CA | MillingBendingFinishingAssembly | ITAR |
| Aeg Industries, Inc Milling, Turning, Bending, Grinding · ISO 9001, ITAR | Santa Rosa, CA | MillingTurningBendingGrinding | ISO 9001, ITAR |
| Aero Mechanism Precision Inc Milling, Assembly · ISO 9001, AS9100 | Chatsworth, CA | MillingAssembly | ISO 9001, AS9100 |
| Aerotech Precision Machining, Inc Milling, Turning, Assembly · ISO 9001, AS9100 | Lancaster, CA | MillingTurningAssembly | ISO 9001, AS9100 |
| Airtronics Metal Products Milling, Laser, Punching, Bending, Welding, Assembly · ISO 9001, ISO 13485 | Morgan Hill, CA | MillingLaserPunchingBendingWeldingAssembly | ISO 9001, ISO 13485 |
| Alex Machining Corp Milling, Turning | San Diego, CA | MillingTurning | - |
| Alloy Metal Products Milling, Turning, EDM, Assembly | Livermore, CA | MillingTurningEDMAssembly | - |
| Alltech Precision Manufacturing Milling, Turning, EDM | Valencia, CA | MillingTurningEDM | - |
| Alpha Aviation Components, Inc Milling, Turning · ISO 9001, AS9100, ITAR | North Hills, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| Alpha Precision CNC, LLC Milling, Turning | Fremont, CA | MillingTurning | - |
| Alziebler Incorporated Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100, ITAR, NADCAP | Arleta, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100, ITAR, NADCAP |
| American CNC Inc Milling, Turning · AS9100 | Pacoima, CA | MillingTurning | AS9100 |
| American Precision Assembly Assembly · ISO 9001, AS9100 | Huntington Beach, CA | Assembly | ISO 9001, AS9100 |
| American Precision Tool & Engineering, Inc Milling, Turning, Swiss, Welding, Grinding, Finishing | Pacoima, CA | MillingTurningSwissWeldingGrindingFinishing | - |
| Angeles Precision Engineering LLC Milling, Turning, Assembly · ISO 9001, ITAR | Ontario, CA | MillingTurningAssembly | ISO 9001, ITAR |
| Apex HT Manufacturing Corp Milling, Turning, Finishing · ISO 9001, ITAR, CMMC | Santa Clara, CA | MillingTurningFinishing | ISO 9001, ITAR, CMMC |
| Atam LLC Milling, Turning · ISO 9001 | Santa Ana, CA | MillingTurning | ISO 9001 |
| Avalon Mfg, Inc Milling · AS9100 | Compton, CA | Milling | AS9100 |
| Axis Product Development, Inc Milling · ITAR | Santa Ana, CA | Milling | ITAR |
| Axxis Corp Milling, Turning, Swiss, Laser · ISO 9001, AS9100, ITAR, ISO 13485 | Perris, CA | MillingTurningSwissLaser | ISO 9001, AS9100, ITAR, ISO 13485 |
| B & F Modern Manufacturing, Inc Milling, Turning, Assembly | Santa Ana, CA | MillingTurningAssembly | - |
| Babbitt Bearing Co Inc Welding, Grinding, Finishing | San Jose, CA | WeldingGrindingFinishing | - |
| Beam on Technology Corporation Laser, Assembly · ITAR | Santa Clara, CA | LaserAssembly | ITAR |
| Beonca Machine Inc Milling, Turning · ISO 9001, AS9100, ITAR | La Verne, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| Beyond Precision, LLC Milling, Turning · ISO 9001, AS9100 | Santa Ana, CA | MillingTurning | ISO 9001, AS9100 |
| BK Customs Bending, Laser, Welding, Waterjet | Riverside, CA | BendingLaserWeldingWaterjet | - |
| Bobco Metals LLC. Welding, Casting | Los Angeles, CA | WeldingCasting | - |
| Brek Manufacturing Co Milling, Assembly | Gardena, CA | MillingAssembly | - |
| Buddy Bar Casting, LLC Milling, Casting | South Gate, CA | MillingCasting | - |
| C & C Machining, Inc Milling, Turning, EDM, Grinding, Finishing | Hayward, CA | MillingTurningEDMGrindingFinishing | - |
| C & S Aerospace, Inc Milling, Turning, EDM | Fullerton, CA | MillingTurningEDM | - |
| Cal Tech Precision Inc Milling, Turning | Anaheim, CA | MillingTurning | - |
| California Manufacturing Inc Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001, AS9100, ITAR | Anaheim, CA | MillingTurningLaserPunchingBendingWelding | ISO 9001, AS9100, ITAR |
| Canady Manufacturing Co Inc Milling, Turning, EDM, Grinding · ISO 9001 | San Fernando, CA | MillingTurningEDMGrinding | ISO 9001 |
| Carney Mfg LLC Milling | Beaumont, CA | Milling | - |
| CB Manufacturing & Engineering Inc Milling, Turning, EDM · ISO 9001, AS9100 | Santa Ana, CA | MillingTurningEDM | ISO 9001, AS9100 |
| Cellpoint Systems, Inc Stamping, Assembly | Fremont, CA | StampingAssembly | - |
| Century Machinery Co Inc Milling, Turning, Bending, Welding | Los Angeles, CA | MillingTurningBendingWelding | - |
| Chromal Plating Co Grinding, Finishing | Los Angeles, CA | GrindingFinishing | - |
| Coast Metal Cutting Turning | San Jose, CA | Turning | - |
| Computer Assisted Manufacturing Technology LLC Milling, Assembly · ISO 9001 | Irvine, CA | MillingAssembly | ISO 9001 |
| Cortec Precision Sheetmetal Milling, Turning, Bending, Laser, Welding | San Jose, CA | MillingTurningBendingLaserWelding | - |
| Coulter Forge, LLC Turning, Forging | Emeryville, CA | TurningForging | - |
| Cutting Edge Manufacturing Milling, Turning, Assembly · ISO 9001, AS9100 | Newbury Park, CA | MillingTurningAssembly | ISO 9001, AS9100 |