| BK Customs Bending, Laser, Welding, Waterjet | Riverside, CA | BendingLaserWeldingWaterjet | - |
| BMW Precision Machining Milling, Turning, Swiss · ITAR | Oceanside, CA | MillingTurningSwiss | ITAR |
| Bob Lewis Machine Company, Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, AS9100 | Gardena, CA | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, AS9100 |
| Braun Co. Engineering LLC Milling, Turning, Swiss, Grinding | Signal Hill, CA | MillingTurningSwissGrinding | - |
| Bullet Fabrication LLC Milling, Bending, Welding | Gardena, CA | MillingBendingWelding | - |
| C & C Machining, Inc Milling, Turning, EDM, Grinding, Finishing | Hayward, CA | MillingTurningEDMGrindingFinishing | - |
| C & S Aerospace, Inc Milling, Turning, EDM | Fullerton, CA | MillingTurningEDM | - |
| C F W Precision Metal Components Waterjet, Assembly · ISO 9001 | Grover Beach, CA | WaterjetAssembly | ISO 9001 |
| Cal Machine & Manufacturing LLC Milling, Turning, Welding, Assembly · ISO 9001, AS9100 | Chino, CA | MillingTurningWeldingAssembly | ISO 9001, AS9100 |
| Calidad, Inc Casting · ISO 9001, AS9100, ITAR | Ontario, CA | Casting | ISO 9001, AS9100, ITAR |
| 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 | - |
| California Sheet Metal Bending, Laser, Welding, Waterjet | El Cajon, CA | BendingLaserWeldingWaterjet | - |
| CalWest MFG Milling, Turning, Laser, Waterjet, Bending, Welding · ISO 9001, ITAR | Fontana, CA | MillingTurningLaserWaterjetBendingWelding | ISO 9001, 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 | - |
| Chromal Plating Co Grinding, Finishing | Los Angeles, CA | GrindingFinishing | - |
| CNC Machining & Engineering Inc Milling, Turning, Swiss | Ontario, CA | MillingTurningSwiss | - |
| Coast Aerospace Manufacturing, Inc Milling, Welding · AS9100, ITAR | Placentia, CA | MillingWelding | AS9100, ITAR |
| Coast Metal Cutting Turning | San Jose, CA | Turning | - |
| Compucraft Industries, Inc Waterjet, Punching, Bending, Welding, EDM, Finishing, Assembly · AS9100, NADCAP | Santee, CA | WaterjetPunchingBendingWeldingEDMFinishingAssembly | AS9100, NADCAP |
| Connelly Machine WKS Milling, Turning, Waterjet, Welding, Grinding · ISO 9001, ITAR | Santa Ana, CA | MillingTurningWaterjetWeldingGrinding | ISO 9001, ITAR |
| Continental Industries Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| CPK Manufacturing Milling, Turning, EDM · ISO 9001 | San Jose, CA | MillingTurningEDM | ISO 9001 |
| Curry Precision Machining LLC Milling, Turning | Winchester, CA | MillingTurning | - |
| Cutting Edge Manufacturing Milling, Turning, Assembly · ISO 9001, AS9100 | Newbury Park, CA | MillingTurningAssembly | ISO 9001, AS9100 |
| D & H Engineering Inc Milling, EDM · AS9100 | Camarillo, CA | MillingEDM | AS9100 |
| Dieform LLC Turning, Punching, Bending, Grinding · ISO 9001, NADCAP | Jurupa Valley, CA | TurningPunchingBendingGrinding | ISO 9001, NADCAP |
| Dinucci Corp Milling, Turning · AS9100 | Concord, CA | MillingTurning | AS9100 |
| DP Machining Inc Milling, Turning, Swiss, Stamping, Finishing | La Verne, CA | MillingTurningSwissStampingFinishing | - |
| DP Products, Inc Milling, Turning, EDM · ISO 9001 | San Jose, CA | MillingTurningEDM | ISO 9001 |
| DT Precision, LLC Milling, Turning, Swiss · ISO 9001, AS9100, ITAR, ISO 13485 | San Jose, CA | MillingTurningSwiss | ISO 9001, AS9100, ITAR, ISO 13485 |
| Dynamic Loop Inc Milling, Turning, Laser, Waterjet, Finishing | Camarillo, CA | MillingTurningLaserWaterjetFinishing | - |
| E2e, Mfg LLC Milling, Casting, EDM | Fremont, CA | MillingCastingEDM | - |
| Eagle Valley Industries, LLC Turning, Waterjet, Bending, Welding | Penn Valley, CA | TurningWaterjetBendingWelding | - |
| Eas Manufacturing Co Milling, Turning, Welding, EDM, Grinding | Camarillo, CA | MillingTurningWeldingEDMGrinding | - |
| Ejays Machine Co Inc Milling, Bending, Assembly · ISO 9001, AS9100 | Fullerton, CA | MillingBendingAssembly | ISO 9001, AS9100 |
| Elco Machine Company Milling, Turning, Finishing | San Luis Obispo, CA | MillingTurningFinishing | - |
| Element Machine Milling, Turning · ISO 9001, AS9100 | Anaheim, CA | MillingTurning | ISO 9001, AS9100 |
| Embee Processing LLC Welding, Finishing | Santa Ana, CA | WeldingFinishing | - |
| Ems Automotive Milling, Turning, Welding, Grinding · ISO 9001, ITAR | Orange, CA | MillingTurningWeldingGrinding | ISO 9001, ITAR |
| Euro Precision, Inc Milling, Turning · ISO 9001, ITAR | Anaheim, CA | MillingTurning | ISO 9001, ITAR |
| Exact CNC Industries Inc Milling, Turning, Swiss, Laser · ISO 9001, AS9100, ITAR | Chatsworth, CA | MillingTurningSwissLaser | ISO 9001, AS9100, ITAR |
| Excel Machining Milling, Turning, Bending, Welding, Waterjet · ISO 9001 | Santa Clara, CA | MillingTurningBendingWeldingWaterjet | ISO 9001 |
| Expedite Precision Works Inc Milling, Turning, Swiss, Welding, EDM, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | San Jose, CA | MillingTurningSwissWeldingEDMFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |
| Fabrication Technologies Industries, Inc Milling, Waterjet, Bending, Welding, Forging | National City, CA | MillingWaterjetBendingWeldingForging | - |
| Fabriquick LLC Milling, Bending | Benicia, CA | MillingBending | - |
| FandJ Precision Milling, Turning, Finishing · ISO 9001, AS9100, ITAR | Gilroy, CA | MillingTurningFinishing | ISO 9001, AS9100, ITAR |