| Marx Digital Manufacturing Inc Milling, Turning, Welding, Assembly | Santa Clara, CA | MillingTurningWeldingAssembly | - |
| Master Metal Products Co Bending, Welding | San Jose, CA | BendingWelding | - |
| Megla Manufacturing, Inc. Milling, Bending, Laser, Welding, Waterjet | National City, CA | MillingBendingLaserWeldingWaterjet | - |
| Metal Fusion Inc Milling, Turning, Welding, Grinding | Redwood City, CA | MillingTurningWeldingGrinding | - |
| Metal Master Inc Milling, Welding | San Diego, CA | MillingWelding | - |
| Metal Masterminds Laser, Waterjet, Punching, Bending, Welding, Stamping | Fountain Valley, CA | LaserWaterjetPunchingBendingWeldingStamping | - |
| Micro-Tec, Inc Milling, Turning, Welding, EDM, Finishing · ISO 9001, AS9100 | Chatsworth, CA | MillingTurningWeldingEDMFinishing | ISO 9001, AS9100 |
| Microform Precision LLC Turning, Bending, Laser, Welding, Waterjet | Sacramento, CA | TurningBendingLaserWeldingWaterjet | - |
| Millennium Metalcraft, Inc Milling, Laser, Bending, Welding, Finishing, Assembly · ISO 9001 | Fremont, CA | MillingLaserBendingWeldingFinishingAssembly | ISO 9001 |
| Miller CNC Milling, Turning, Welding, Grinding · ISO 9001, AS9100 | Chula Vista, CA | MillingTurningWeldingGrinding | ISO 9001, AS9100 |
| Miramar Metal Processing Inc Welding, Finishing · ITAR, NADCAP | San Diego, CA | WeldingFinishing | ITAR, NADCAP |
| Mono Engineering Corp Turning, Welding, EDM · ISO 9001 | Chatsworth, CA | TurningWeldingEDM | ISO 9001 |
| Nace Sheet Metal Co Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| National Metal Stampings - Temecula Valley Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Lancaster, CA | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Neff Engineering LLC Milling, Laser, Welding | Los Angeles, CA | MillingLaserWelding | - |
| Next Intent, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, ITAR | San Luis Obispo, CA | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, ITAR |
| Next Tech Manufacturing Inc Milling, Welding, Finishing | Santa Clara, CA | MillingWeldingFinishing | - |
| Nexus Automation Milling, Welding, EDM, Assembly · ISO 9001, ITAR, ISO 13485 | Livermore, CA | MillingWeldingEDMAssembly | ISO 9001, ITAR, ISO 13485 |
| Optima Precision Milling, Turning, Bending, Welding, EDM, Metal AM · ISO 9001, AS9100, ISO 13485, NADCAP | San Jose, CA | MillingTurningBendingWeldingEDMMetal AM | ISO 9001, AS9100, ISO 13485, NADCAP |
| Pacific Maritime Industries Corp Milling, Turning, Laser, Waterjet, Punching, Bending, Welding · ISO 9001 | San Diego, CA | MillingTurningLaserWaterjetPunchingBendingWelding | ISO 9001 |
| Parallax Manufacturing LLC Milling, Turning, Bending, Welding, Stamping, Assembly · NADCAP | Lake Elsinore, CA | MillingTurningBendingWeldingStampingAssembly | NADCAP |
| Peridot Corp Laser, Welding | Pleasanton, CA | LaserWelding | - |
| Pimtad Aerospace LLC Milling, Turning, Swiss, Welding, Grinding, Assembly · AS9100 | Valencia, CA | MillingTurningSwissWeldingGrindingAssembly | AS9100 |
| Prisecter Aerospace and Defense LLC Milling, Turning, Waterjet, Welding, Assembly · AS9100, ITAR, CMMC | Auburn, CA | MillingTurningWaterjetWeldingAssembly | AS9100, ITAR, CMMC |
| Process Stainless Lab Welding, Finishing, Assembly · ISO 9001 | Milpitas, CA | WeldingFinishingAssembly | ISO 9001 |
| Pure Source Welding, Finishing | Fontana, CA | WeldingFinishing | - |
| Quality Grinding Co, Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100 | Buena Park, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100 |
| Quantum Machining & Design Inc. Bending, Laser, Welding | Fresno, CA | BendingLaserWelding | - |
| Rache Corp Laser, Welding · ISO 9001, AS9100, ITAR | Camarillo, CA | LaserWelding | ISO 9001, AS9100, ITAR |
| Radical Fabrications LLC Milling, Turning, Welding, Grinding | Lancaster, CA | MillingTurningWeldingGrinding | - |
| Rah Industries Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100, NADCAP | Santa Clarita, CA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100, NADCAP |
| Ramda Metal Specialities Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping · ISO 9001 | Gardena, CA | MillingTurningLaserWaterjetPunchingBendingWeldingStamping | ISO 9001 |
| Rand Machine Works Milling, Turning, Bending, Welding | Fresno, CA | MillingTurningBendingWelding | - |
| Redwood Machine Works, Inc Waterjet, Welding · ISO 9001, AS9100 | Oakland, CA | WaterjetWelding | ISO 9001, AS9100 |
| Responsible Metal Fab Inc Welding, Finishing, Assembly · ISO 9001 | Sunnyvale, CA | WeldingFinishingAssembly | ISO 9001 |
| Rieker Machine LLC Welding, Assembly | Carlsbad, CA | WeldingAssembly | - |
| Rincon Engineering Corporation Milling, Turning, Laser, Waterjet, Punching, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Carpinteria, CA | MillingTurningLaserWaterjetPunchingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| Rivtec LLC Laser, Bending, Welding, Assembly | Santa Ana, CA | LaserBendingWeldingAssembly | - |
| Roller Technologies Co Milling, Turning, Welding, Finishing, Assembly | Upland, CA | MillingTurningWeldingFinishingAssembly | - |
| S & S Commercial Fishing Equipment, Incorporated Milling, Turning, Welding | Roseville, CA | MillingTurningWelding | - |
| San Diego Precision Machining Inc Milling, Turning, Welding, EDM · ISO 9001, AS9100 | San Diego, CA | MillingTurningWeldingEDM | ISO 9001, AS9100 |
| Scotia Engineering, Inc Milling, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Assembly | Santa Fe Springs, CA | MillingWaterjetBendingWeldingStampingEDMGrindingAssembly | - |
| Sheetmetal Engineering Inc Milling, Laser, Punching, Bending, Welding · ISO 9001, AS9100 | Simi Valley, CA | MillingLaserPunchingBendingWelding | ISO 9001, AS9100 |
| 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 |
| Slag Factory Milling, Laser, Welding | Oroville, CA | MillingLaserWelding | - |
| Stigtec Manufacturing Milling, Welding, EDM, Grinding, Finishing, Assembly | San Marcos, CA | MillingWeldingEDMGrindingFinishingAssembly | - |
| Stockton Tri-Industries, LLC Milling, Turning, Waterjet, Bending, Welding, Assembly | Stockton, CA | MillingTurningWaterjetBendingWeldingAssembly | - |
| Suntiger Industries LLC Welding · ISO 9001, AS9100, ITAR | Oceanside, CA | Welding | ISO 9001, AS9100, ITAR |
| Superior Pipe Fabricators Welding | Los Angeles, CA | Welding | - |