| 6S Machining Enterprises LLC Milling, Welding · ISO 9001, AS9100, ITAR, NADCAP | San Marcos, CA | MillingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| A & D Precision Machining, Inc Milling, Assembly · ISO 13485 | Fremont, CA | MillingAssembly | ISO 13485 |
| A & D Precision Manufacturing Milling, Turning, Bending, Welding · ISO 9001, AS9100, ITAR | Anaheim, CA | MillingTurningBendingWelding | ISO 9001, AS9100, ITAR |
| A & M Engineering Inc Milling | Irwindale, CA | Milling | - |
| A.m.i. Engineering Co LLC Milling, Turning, Finishing · ISO 9001, ITAR | Santa Ana, CA | MillingTurningFinishing | ISO 9001, ITAR |
| A&A Machine Milling, Swiss, EDM · AS9100 | Gardena, CA | MillingSwissEDM | AS9100 |
| A&k Manufacturing Inc Turning, Welding, Assembly | Sun Valley, CA | TurningWeldingAssembly | - |
| Abc Sheet Metal Laser, Waterjet, Punching, Bending, Welding · ISO 9001, AS9100 | Anaheim, CA | LaserWaterjetPunchingBendingWelding | ISO 9001, AS9100 |
| Accurate Metal Products Milling, Punching, Bending, Welding | Jurupa Valley, CA | MillingPunchingBendingWelding | - |
| Ace Clearwater Enterprises Inc Milling, Laser, Waterjet, Bending, Welding, Casting | Torrance, CA | MillingLaserWaterjetBendingWeldingCasting | - |
| Additive Plus Metal AM · AS9100, ITAR, NADCAP, ISO 13485 | Sherman Oaks, CA | Metal AM | AS9100, ITAR, NADCAP, ISO 13485 |
| Advance Metal Products Bending, Welding | Los Angeles, CA | BendingWelding | - |
| 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 |
| Aerotech Precision Machining, Inc Milling, Turning, Assembly · ISO 9001, AS9100 | Lancaster, CA | MillingTurningAssembly | ISO 9001, AS9100 |
| Alex Machining Corp Milling, Turning | San Diego, CA | MillingTurning | - |
| All American Metal Fabrication Bending, Laser, Welding, Waterjet | Anaheim, CA | BendingLaserWeldingWaterjet | - |
| All Materials Manufacturing Co LLC Milling, Turning, Swiss, Finishing · ISO 9001, AS9100, ITAR | Riverside, CA | MillingTurningSwissFinishing | ISO 9001, AS9100, ITAR |
| All New Stamping Co Laser, Punching, Bending, Stamping, Grinding · ISO 9001, AS9100 | El Monte, CA | LaserPunchingBendingStampingGrinding | ISO 9001, AS9100 |
| All-Around Fabrication Inc Milling, Laser, Bending, Welding · ITAR | Sacramento, CA | MillingLaserBendingWelding | ITAR |
| All-In Machining LLC Milling, Turning | Tracy, CA | MillingTurning | - |
| All-Ways Metal Inc Milling, Turning, Laser, Punching, Bending, Welding, Grinding · ISO 9001, ITAR | Gardena, CA | MillingTurningLaserPunchingBendingWeldingGrinding | ISO 9001, ITAR |
| Alloy Metal Products Milling, Turning, EDM, Assembly | Livermore, CA | MillingTurningEDMAssembly | - |
| Alpha Aviation Components, Inc Milling, Turning · ISO 9001, AS9100, ITAR | North Hills, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| Alziebler Incorporated Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100, ITAR, NADCAP | Arleta, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100, ITAR, NADCAP |
| Amador Steel and Supply, LLC Milling, Punching, Bending, Welding | Jackson, CA | MillingPunchingBendingWelding | - |
| Amex Plating Inc Finishing | Santa Clara, CA | Finishing | - |
| AMS Manufacturing Welding, EDM, Finishing, Assembly | San Jose, CA | WeldingEDMFinishingAssembly | - |
| Angeles Precision Engineering LLC Milling, Turning, Assembly · ISO 9001, ITAR | Ontario, CA | MillingTurningAssembly | ISO 9001, ITAR |
| Ap Precision Metals, Inc Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly · ISO 9001 | San Diego, CA | LaserPunchingBendingWeldingStampingFinishingAssembly | ISO 9001 |
| APV Manufacturing Milling, Waterjet, Bending, Welding, Grinding · NADCAP | Buena Park, CA | MillingWaterjetBendingWeldingGrinding | NADCAP |
| Ascend Mfg Corp Milling, Laser, Welding, Stamping, Finishing | Anaheim, CA | MillingLaserWeldingStampingFinishing | - |
| 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 | - |
| B & Z Manufacturing Co Inc Milling, Turning, Grinding · ISO 9001 | San Jose, CA | MillingTurningGrinding | ISO 9001 |
| Bell Machine Works Milling, Finishing · ISO 9001, ITAR | Gilroy, CA | MillingFinishing | ISO 9001, 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 |
| Beonca Machine Inc Milling, Turning · ISO 9001, AS9100, ITAR | La Verne, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| BK Customs Bending, Laser, Welding, Waterjet | Riverside, CA | BendingLaserWeldingWaterjet | - |
| 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 | - |
| Bobco Metals LLC. Welding, Casting | Los Angeles, CA | WeldingCasting | - |
| Britech Electropolishing Inc Welding, Finishing | Newark, CA | WeldingFinishing | - |
| Buddy Bar Casting, LLC Milling, Casting | South Gate, CA | MillingCasting | - |
| Bullet Fabrication LLC Milling, Bending, Welding | Gardena, CA | MillingBendingWelding | - |
| C & W Manufacturing Milling, Turning, Welding, Grinding, Finishing · ISO 9001, ITAR, CMMC | Turlock, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, ITAR, CMMC |
| 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 |