| Jaco Engineering Milling, Turning, Bending, Welding, EDM, Grinding, Finishing, Assembly · NADCAP | Anaheim, CA | MillingTurningBendingWeldingEDMGrindingFinishingAssembly | NADCAP |
| Jaffa Precision Engineering Inc Milling, Turning, Swiss, Welding, Grinding, Finishing · ISO 9001 | Riverside, CA | MillingTurningSwissWeldingGrindingFinishing | ISO 9001 |
| Jars Inc Milling, Waterjet, Bending, Welding, EDM, Grinding, Finishing | San Fernando, CA | MillingWaterjetBendingWeldingEDMGrindingFinishing | - |
| Joels Machine Shop Inc Milling, Turning, Grinding | El Monte, CA | MillingTurningGrinding | - |
| Johnson Manufacturing Milling, Turning, Grinding · AS9100 | Huntington Beach, CA | MillingTurningGrinding | AS9100 |
| L & R Machine Inc Milling, Turning, Grinding | Rancho Cucamonga, CA | MillingTurningGrinding | - |
| L&B Labs Milling, Turning, Laser, Welding, EDM, Grinding | San Jose, CA | MillingTurningLaserWeldingEDMGrinding | - |
| La Gauge Co Milling, Turning, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR | Sun Valley, CA | MillingTurningEDMGrindingFinishing | ISO 9001, AS9100, ITAR |
| Lam Precision, Inc Milling, Grinding · AS9100 | Anaheim, CA | MillingGrinding | AS9100 |
| Long Machine Milling, Turning, Grinding | Temecula, CA | MillingTurningGrinding | - |
| LP Precision, Inc Milling, Turning, Grinding, Finishing | Santa Clara, CA | MillingTurningGrindingFinishing | - |
| Mac Smith Corp Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, Grinding | Gardena, CA | MillingTurningLaserWaterjetBendingWeldingStampingGrinding | - |
| Mars Engineering Milling, Turning, Waterjet, EDM, Grinding, Finishing, Assembly | San Leandro, CA | MillingTurningWaterjetEDMGrindingFinishingAssembly | - |
| McKenzie Machining Inc Milling, Turning, EDM, Grinding · ISO 9001, AS9100, ITAR | San Jose, CA | MillingTurningEDMGrinding | ISO 9001, AS9100, ITAR |
| Metal Fusion Inc Milling, Turning, Welding, Grinding | Redwood City, CA | MillingTurningWeldingGrinding | - |
| Micro Space Products Turning, Grinding · ISO 9001, ITAR | Torrance, CA | TurningGrinding | ISO 9001, ITAR |
| Miller CNC Milling, Turning, Welding, Grinding · ISO 9001, AS9100 | Chula Vista, CA | MillingTurningWeldingGrinding | ISO 9001, AS9100 |
| Milo Engineering Milling, Turning, Grinding, Finishing · ISO 9001 | Torrance, CA | MillingTurningGrindingFinishing | ISO 9001 |
| MVC Wire Milling, Turning, EDM, Grinding · ISO 9001 | Mission Viejo, CA | MillingTurningEDMGrinding | ISO 9001 |
| National Metal Stampings - Temecula Valley Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Lancaster, CA | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Next Intent, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, ITAR | San Luis Obispo, CA | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, ITAR |
| Noron Precision Machining Inc Milling, Turning, Grinding, Finishing, Assembly · ISO 9001, ITAR | Sunnyvale, CA | MillingTurningGrindingFinishingAssembly | ISO 9001, ITAR |
| Petersen Precision Engineering LLC Milling, Turning, Swiss, EDM, Grinding, Finishing · ISO 9001, AS9100, ISO 13485 | Redwood City, CA | MillingTurningSwissEDMGrindingFinishing | ISO 9001, AS9100, ISO 13485 |
| Pimtad Aerospace LLC Milling, Turning, Swiss, Welding, Grinding, Assembly · AS9100 | Valencia, CA | MillingTurningSwissWeldingGrindingAssembly | AS9100 |
| Powers Bros Machine Inc Welding, Grinding | Montebello, CA | WeldingGrinding | - |
| Precision Ferrites & Ceramic Milling, Grinding · AS9100 | Huntington Beach, CA | MillingGrinding | AS9100 |
| PTG Precision LLC Milling, Turning, Swiss, Welding, Grinding, Assembly · ISO 9001, AS9100, ITAR, CMMC | Gardena, CA | MillingTurningSwissWeldingGrindingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Qualitask Inc Milling, Turning, Swiss, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Anaheim, CA | MillingTurningSwissWeldingEDMGrindingFinishingAssembly | ISO 9001, AS9100 |
| Quality Controlled Manufacturing Inc Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100, ITAR, NADCAP | Santee, CA | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100, ITAR, NADCAP |
| Quality Grinding Co, Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100 | Buena Park, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100 |
| R.M. Baker Machine & Tool, Inc Milling, Welding, EDM, Grinding, Finishing | Covina, CA | MillingWeldingEDMGrindingFinishing | - |
| R2 Precision Machining LLC Milling, Turning, Forging, Grinding · ISO 9001 | Rancho Cucamonga, CA | MillingTurningForgingGrinding | ISO 9001 |
| Radical Fabrications LLC Milling, Turning, Welding, Grinding | Lancaster, CA | MillingTurningWeldingGrinding | - |
| Ram Aerospace Inc Milling, Turning, Laser, Waterjet, EDM, Grinding, Assembly · AS9100, ITAR | Brea, CA | MillingTurningLaserWaterjetEDMGrindingAssembly | AS9100, ITAR |
| RB Machining, Inc Milling, Turning, Grinding · AS9100 | Palmdale, CA | MillingTurningGrinding | AS9100 |
| Royal Coatings Grinding, Finishing | Simi Valley, CA | GrindingFinishing | - |
| Santa Lucia Manufacturing, Inc Milling, Turning, Grinding | Atascadero, CA | MillingTurningGrinding | - |
| Schneiders Manufacturing Inc Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100, ITAR | Sun Valley, CA | MillingTurningSwissEDMGrinding | ISO 9001, AS9100, ITAR |
| Scotia Engineering, Inc Milling, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Assembly | Santa Fe Springs, CA | MillingWaterjetBendingWeldingStampingEDMGrindingAssembly | - |
| SDS Engineering Milling, Turning, Grinding · ISO 9001 | Sun Valley, CA | MillingTurningGrinding | ISO 9001 |
| Serrano Industries, Inc Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100 | Santa Fe Springs, CA | MillingTurningSwissEDMGrinding | ISO 9001, AS9100 |
| Sharp Dimension Inc Milling, Turning, Bending, Welding, Grinding, Finishing, Assembly · ISO 9001, ITAR | Fremont, CA | MillingTurningBendingWeldingGrindingFinishingAssembly | ISO 9001, ITAR |
| Silicon Valley Precision Inc Milling, Turning, Welding, Casting, Grinding, Finishing · ITAR | Livermore, CA | MillingTurningWeldingCastingGrindingFinishing | ITAR |
| SJC Precision Inc Milling, Laser, Punching, Welding, Stamping, Grinding · ISO 9001, ITAR | Milpitas, CA | MillingLaserPunchingWeldingStampingGrinding | ISO 9001, ITAR |
| Stigtec Manufacturing Milling, Welding, EDM, Grinding, Finishing, Assembly | San Marcos, CA | MillingWeldingEDMGrindingFinishingAssembly | - |
| Superior Thread Rolling Co, LLC Milling, Turning, Grinding · ISO 9001, AS9100, NADCAP | Arleta, CA | MillingTurningGrinding | ISO 9001, AS9100, NADCAP |
| Swiss Screw Products Inc Milling, Turning, Swiss, Grinding, Assembly · ISO 9001 | Santa Clara, CA | MillingTurningSwissGrindingAssembly | ISO 9001 |
| T&K Machine Milling, Turning, Welding, EDM, Grinding | Livermore, CA | MillingTurningWeldingEDMGrinding | - |
| ThermoAir Grinding | Burbank, CA | Grinding | - |
| Trabuco Precision LLC Milling, Turning, Grinding · ISO 9001, AS9100 | Yorba Linda, CA | MillingTurningGrinding | ISO 9001, AS9100 |