| M&M Machining, Inc Milling, Turning, Welding, Finishing | Ventura, CA | MillingTurningWeldingFinishing | - |
| Mars Engineering Milling, Turning, Waterjet, EDM, Grinding, Finishing, Assembly | San Leandro, CA | MillingTurningWaterjetEDMGrindingFinishingAssembly | - |
| Metal Fusion Inc Milling, Turning, Welding, Grinding | Redwood City, CA | MillingTurningWeldingGrinding | - |
| Milner's Anodizing Finishing · NADCAP | Santa Rosa, CA | Finishing | NADCAP |
| Miramar Metal Processing Inc Welding, Finishing · ITAR, NADCAP | San Diego, CA | WeldingFinishing | ITAR, NADCAP |
| MKM Manufacturing & Design, Inc Finishing | Newbury Park, CA | Finishing | - |
| Next Tech Manufacturing Inc Milling, Welding, Finishing | Santa Clara, CA | MillingWeldingFinishing | - |
| PCL, LLC Milling, Turning, Swiss, Finishing · NADCAP | Oxnard, CA | MillingTurningSwissFinishing | NADCAP |
| Powers Bros Machine Inc Welding, Grinding | Montebello, CA | WeldingGrinding | - |
| Pure Source Welding, Finishing | Fontana, CA | WeldingFinishing | - |
| Ram Aerospace Inc Milling, Turning, Laser, Waterjet, EDM, Grinding, Assembly · AS9100, ITAR | Brea, CA | MillingTurningLaserWaterjetEDMGrindingAssembly | AS9100, ITAR |
| Ramp Engineering Inc Milling, Turning, Swiss | Paramount, CA | MillingTurningSwiss | - |
| RBH Aerospace Inc Milling, Turning, Waterjet, Bending | Lakewood, CA | MillingTurningWaterjetBending | - |
| Roller Technologies Co Milling, Turning, Welding, Finishing, Assembly | Upland, CA | MillingTurningWeldingFinishingAssembly | - |
| Royal Coatings Grinding, Finishing | Simi Valley, CA | GrindingFinishing | - |
| Schulte Corporation Milling, Turning, Welding, Finishing · NADCAP | San Clemente, CA | MillingTurningWeldingFinishing | NADCAP |
| Stigtec Manufacturing Milling, Welding, EDM, Grinding, Finishing, Assembly | San Marcos, CA | MillingWeldingEDMGrindingFinishingAssembly | - |
| Tri Models Inc Milling, Turning, EDM, Finishing, Assembly | Huntington Beach, CA | MillingTurningEDMFinishingAssembly | - |
| 3-D Machine Co Milling | Anaheim, CA | Milling | - |
| A & M Engineering Inc Milling | Irwindale, CA | Milling | - |
| A&k Manufacturing Inc Turning, Welding, Assembly | Sun Valley, CA | TurningWeldingAssembly | - |
| Abacorp CNC Machined Parts Milling, Turning, Laser, Welding · AS9100 | Moorpark, CA | MillingTurningLaserWelding | AS9100 |
| Absolute Machining, Inc Milling, Turning | Chatsworth, CA | MillingTurning | - |
| AC Manufacturing Milling, Turning, Welding | San Jose, CA | MillingTurningWelding | - |
| Acosta Sheet Metal Manufacturing Bending | San Jose, CA | Bending | - |
| Advance Metal Products Bending, Welding | Los Angeles, CA | BendingWelding | - |
| Advanced Fabrication Bending, Welding, Waterjet | Bakersfield, CA | BendingWeldingWaterjet | - |
| Aerospace Manufacturing Inc Welding, Assembly · AS9100 | Canyon Countrt, CA | WeldingAssembly | AS9100 |
| Alex Machining Corp Milling, Turning | San Diego, CA | MillingTurning | - |
| All American Metal Fabrication Bending, Laser, Welding, Waterjet | Anaheim, CA | BendingLaserWeldingWaterjet | - |
| All-Around Fabrication Inc Milling, Laser, Bending, Welding · ITAR | Sacramento, CA | MillingLaserBendingWelding | ITAR |
| All-In Machining LLC Milling, Turning | Tracy, CA | MillingTurning | - |
| Allied Mechanical Milling, Turning, Bending, Welding, EDM, Grinding, Assembly | Ontario, CA | MillingTurningBendingWeldingEDMGrindingAssembly | - |
| Alloy Metal Products Milling, Turning, EDM, Assembly | Livermore, CA | MillingTurningEDMAssembly | - |
| Amador Steel and Supply, LLC Milling, Punching, Bending, Welding | Jackson, CA | MillingPunchingBendingWelding | - |
| American CNC Inc Milling, Turning · AS9100 | Pacoima, CA | MillingTurning | AS9100 |
| 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 | - |
| B & F Modern Manufacturing, Inc Milling, Turning, Assembly | Santa Ana, CA | MillingTurningAssembly | - |
| Babbitt Bearing Co Inc Welding, Grinding, Finishing | San Jose, CA | WeldingGrindingFinishing | - |
| BK Customs Bending, Laser, Welding, Waterjet | Riverside, CA | BendingLaserWeldingWaterjet | - |
| Brek Manufacturing Co Milling, Assembly | Gardena, CA | MillingAssembly | - |
| BS Designs Inc Milling, Turning, Welding | Santee, CA | MillingTurningWelding | - |
| 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 | - |
| C & S Aerospace, Inc Milling, Turning, EDM | Fullerton, CA | MillingTurningEDM | - |
| California Lasers Inc Milling, Laser, Welding, EDM, Grinding | Simi Valley, CA | MillingLaserWeldingEDMGrinding | - |
| Carney Mfg LLC Milling | Beaumont, CA | Milling | - |