| Ascend Mfg Corp Milling, Laser, Welding, Stamping, Finishing | Anaheim, CA | MillingLaserWeldingStampingFinishing | - |
| Atmosphere Machining LLC Milling, Turning, Waterjet, Welding, Finishing · ITAR | Tehachapi, CA | MillingTurningWaterjetWeldingFinishing | ITAR |
| Avalon Mfg, Inc Milling · AS9100 | Compton, CA | Milling | AS9100 |
| Axis Product Development, Inc Milling · ITAR | Santa Ana, CA | Milling | ITAR |
| Axton Robotics LLC Milling, Turning, Finishing | San Diego, CA | MillingTurningFinishing | - |
| B & D Precision Welding Milling, Turning, Welding, Grinding | Pomona, CA | MillingTurningWeldingGrinding | - |
| 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 |
| Bell Machine Works Milling, Finishing · ISO 9001, ITAR | Gilroy, CA | MillingFinishing | ISO 9001, ITAR |
| Benen Manufacturing LLC Milling, Turning, Welding, Finishing, Assembly · ISO 9001, ISO 13485 | San Jose, CA | MillingTurningWeldingFinishingAssembly | ISO 9001, ISO 13485 |
| 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 |
| 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 |
| Bob’s Welding, Machining & Fabrication, Inc. Bending, Welding | Anaheim, CA | BendingWelding | - |
| Braun Co. Engineering LLC Milling, Turning, Swiss, Grinding | Signal Hill, CA | MillingTurningSwissGrinding | - |
| BS Designs Inc Milling, Turning, Welding | Santee, CA | MillingTurningWelding | - |
| Buddy Bar Casting, LLC Milling, Casting | South Gate, CA | MillingCasting | - |
| Bullet Fabrication LLC Milling, Bending, Welding | Gardena, CA | MillingBendingWelding | - |
| Burnet Machining Inc Milling, Turning | Goleta, CA | MillingTurning | - |
| C & C Machining, Inc Milling, Turning, EDM, Grinding, Finishing | Hayward, CA | MillingTurningEDMGrindingFinishing | - |
| Cal Machine & Manufacturing LLC Milling, Turning, Welding, Assembly · ISO 9001, AS9100 | Chino, CA | MillingTurningWeldingAssembly | ISO 9001, AS9100 |
| Cal Tech Precision Inc Milling, Turning | Anaheim, CA | MillingTurning | - |
| Calidad, Inc Casting · ISO 9001, AS9100, ITAR | Ontario, CA | Casting | ISO 9001, AS9100, ITAR |
| California Manufacturing Inc Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001, AS9100, ITAR | Anaheim, CA | MillingTurningLaserPunchingBendingWelding | ISO 9001, AS9100, ITAR |
| 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 |
| Canady Manufacturing Co Inc Milling, Turning, EDM, Grinding · ISO 9001 | San Fernando, CA | MillingTurningEDMGrinding | ISO 9001 |
| Caran Precision Engineering & Manufacturing Corp Milling, Turning, Swiss, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, IATF 16949 | Brea, CA | MillingTurningSwissWeldingStampingEDMGrindingAssembly | ISO 9001, IATF 16949 |
| Carney Mfg LLC Milling | Beaumont, CA | Milling | - |
| Casco Machining Inc. Milling, Turning, Welding · ISO 9001 | San Jose, CA | MillingTurningWelding | ISO 9001 |
| 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 | - |
| Charles Meisner, Inc Milling, Turning, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | Upland, CA | MillingTurningBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| Clint Precision Manufacturing Milling, Turning, Welding, Waterjet · ISO 9001 | San Diego, CA | MillingTurningWeldingWaterjet | ISO 9001 |
| CNC Machining & Engineering Inc Milling, Turning, Swiss | Ontario, CA | MillingTurningSwiss | - |
| Coast Precision Enterprises Milling, Turning · ISO 9001, AS9100, ITAR | San Diego, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| Colleen & Herb Enterprises Inc Milling, Turning, Welding | Fremont, CA | MillingTurningWelding | - |
| Component Surfaces Inc Finishing · ISO 9001, ITAR | Poway, CA | Finishing | ISO 9001, ITAR |
| 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 | - |
| Cortec Precision Sheetmetal Milling, Turning, Bending, Laser, Welding | San Jose, CA | MillingTurningBendingLaserWelding | - |
| CPK Manufacturing Milling, Turning, EDM · ISO 9001 | San Jose, CA | MillingTurningEDM | ISO 9001 |
| Crater Industries LLC Milling, Turning, EDM, Grinding, Assembly | Santa Clarita, CA | MillingTurningEDMGrindingAssembly | - |
| Curry Precision Machining LLC Milling, Turning | Winchester, CA | MillingTurning | - |
| Custom Machine Milling · ISO 9001 | San Luis Obispo, CA | Milling | ISO 9001 |
| D & H Engineering Inc Milling, EDM · AS9100 | Camarillo, CA | MillingEDM | AS9100 |
| Daico Precision LLC Milling, Turning, Grinding, Finishing, Assembly | Garden Grove, CA | MillingTurningGrindingFinishingAssembly | - |