| PCL, LLC Milling, Turning, Swiss, Finishing · NADCAP | Oxnard, CA | MillingTurningSwissFinishing | NADCAP |
| Pegasus Machining Solutions Milling, Turning, Finishing | San Jose, CA | MillingTurningFinishing | - |
| Petersen Precision Engineering LLC Milling, Turning, Swiss, EDM, Grinding, Finishing · ISO 9001, AS9100, ISO 13485 | Redwood City, CA | MillingTurningSwissEDMGrindingFinishing | ISO 9001, AS9100, ISO 13485 |
| PL Machine Corporation Milling, Turning, Bending, Finishing · ISO 9001 | Los Alamitos, CA | MillingTurningBendingFinishing | ISO 9001 |
| Process Stainless Lab Welding, Finishing, Assembly · ISO 9001 | Milpitas, CA | WeldingFinishingAssembly | ISO 9001 |
| Pure Source Welding, Finishing | Fontana, CA | WeldingFinishing | - |
| Qualitask Inc Milling, Turning, Swiss, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Anaheim, CA | MillingTurningSwissWeldingEDMGrindingFinishingAssembly | ISO 9001, AS9100 |
| Quality Grinding Co, Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001, AS9100 | Buena Park, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, AS9100 |
| Quality Thermal Applications Stamping, EDM, Finishing | Anaheim, CA | StampingEDMFinishing | - |
| R.M. Baker Machine & Tool, Inc Milling, Welding, EDM, Grinding, Finishing | Covina, CA | MillingWeldingEDMGrindingFinishing | - |
| Radian Thermal Products, Inc Milling, Casting, Finishing · ISO 9001, ITAR | Santa Clara, CA | MillingCastingFinishing | ISO 9001, ITAR |
| Rah Industries Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100, NADCAP | Santa Clarita, CA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100, NADCAP |
| Responsible Metal Fab Inc Welding, Finishing, Assembly · ISO 9001 | Sunnyvale, CA | WeldingFinishingAssembly | ISO 9001 |
| Ricaurte Precision Inc Milling, Turning, Swiss, Laser, EDM, Finishing, Assembly · ISO 9001, ITAR | Santa Ana, CA | MillingTurningSwissLaserEDMFinishingAssembly | ISO 9001, ITAR |
| Rincon Engineering Corporation Milling, Turning, Laser, Waterjet, Punching, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Carpinteria, CA | MillingTurningLaserWaterjetPunchingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| Roller Technologies Co Milling, Turning, Welding, Finishing, Assembly | Upland, CA | MillingTurningWeldingFinishingAssembly | - |
| Royal Coatings Grinding, Finishing | Simi Valley, CA | GrindingFinishing | - |
| Savage Machining Inc Milling, Turning, EDM, Finishing, Assembly · ISO 9001 | Simi Valley, CA | MillingTurningEDMFinishingAssembly | ISO 9001 |
| Schulte Corporation Milling, Turning, Welding, Finishing · NADCAP | San Clemente, CA | MillingTurningWeldingFinishing | NADCAP |
| 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 |
| Snowline Engineering Laser, Waterjet, Welding, Finishing · ISO 9001, AS9100, NADCAP | Cameron Park, CA | LaserWaterjetWeldingFinishing | ISO 9001, AS9100, NADCAP |
| SP Manufacturing Inc Milling, Turning, Welding, Finishing · ISO 9001, AS9100 | Livermore, CA | MillingTurningWeldingFinishing | ISO 9001, AS9100 |
| Stigtec Manufacturing Milling, Welding, EDM, Grinding, Finishing, Assembly | San Marcos, CA | MillingWeldingEDMGrindingFinishingAssembly | - |
| Support Equipment Inc Milling, Turning, Welding, EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR | Escondido, CA | MillingTurningWeldingEDMFinishingAssembly | ISO 9001, AS9100, ITAR |
| T & T Metals Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001 | Covina, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001 |
| Tiger Precision Machining Milling, Turning, Welding, Finishing | Lodi, CA | MillingTurningWeldingFinishing | - |
| Top Machining, Inc Milling, Turning, Welding, Finishing, Assembly · ISO 9001, AS9100, ITAR | Santa Clara, CA | MillingTurningWeldingFinishingAssembly | ISO 9001, AS9100, ITAR |
| Tri Fab Associates, Inc Milling, Turning, Laser, Punching, Welding, Stamping, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, CMMC | Fremont, CA | MillingTurningLaserPunchingWeldingStampingGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Tri Models Inc Milling, Turning, EDM, Finishing, Assembly | Huntington Beach, CA | MillingTurningEDMFinishingAssembly | - |
| Tridecs Corp Milling, Swiss, EDM, Grinding, Finishing, Assembly · ISO 9001 | Hayward, CA | MillingSwissEDMGrindingFinishingAssembly | ISO 9001 |
| Trinity Machining, LLC Milling, Turning, Bending, EDM, Grinding, Finishing · ISO 9001 | Grass Valley, CA | MillingTurningBendingEDMGrindingFinishing | ISO 9001 |
| True Precision Machining, Inc Milling, Turning, Swiss, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR, CMMC | Buellton, CA | MillingTurningSwissWeldingStampingEDMGrindingFinishing | ISO 9001, AS9100, ITAR, CMMC |
| United Sheetmetal Inc Laser, Punching, Welding, Stamping, Casting, EDM, Finishing · ISO 9001 | Fremont, CA | LaserPunchingWeldingStampingCastingEDMFinishing | ISO 9001 |
| Verdugo Tool & Engineering Co Inc Laser, Punching, Bending, Stamping, EDM, Grinding, Finishing · ISO 9001, ITAR | Chatsworth, CA | LaserPunchingBendingStampingEDMGrindingFinishing | ISO 9001, ITAR |
| Vicon Precision, Ltd. Liability Co Milling, Turning, Welding, Finishing, Assembly · ISO 9001 | San Jose, CA | MillingTurningWeldingFinishingAssembly | ISO 9001 |
| Vinaco Precision Machining, LLC Milling, Turning, Grinding, Finishing · ISO 9001, AS9100, NADCAP | Chatsworth, CA | MillingTurningGrindingFinishing | ISO 9001, AS9100, NADCAP |
| Vista Industries, Inc Welding, Finishing | Palmdale, CA | WeldingFinishing | - |
| Yuhas Tooling & Machining Inc Milling, Turning, Grinding, Finishing | Milpitas, CA | MillingTurningGrindingFinishing | - |