| Pen Manufacturing Milling, Turning, Bending, Welding · ISO 9001, AS9100, ITAR, NADCAP | Anaheim, CA | MillingTurningBendingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| Perforated Panels Laser, Waterjet, Bending, Welding | Pacoima, CA | LaserWaterjetBendingWelding | - |
| Pervan Industries Milling, Turning, Waterjet, Punching, Bending · ISO 9001, AS9100 | Compton, CA | MillingTurningWaterjetPunchingBending | ISO 9001, AS9100 |
| PL Machine Corporation Milling, Turning, Bending, Finishing · ISO 9001 | Los Alamitos, CA | MillingTurningBendingFinishing | ISO 9001 |
| Precision Machining & Fab Milling, Turning, Bending, Laser, Welding, Waterjet · ISO 9001, AS9100, ITAR | Anaheim, CA | MillingTurningBendingLaserWeldingWaterjet | ISO 9001, AS9100, ITAR |
| Prism Aerospace Bending, Assembly · AS9100, CMMC | Riverside, CA | BendingAssembly | AS9100, CMMC |
| Pro-Tek Manufacturing Inc Bending, Welding | Livermore, CA | BendingWelding | - |
| Prototek Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting, Metal AM · ISO 9001, AS9100, ITAR, CMMC | Rancho Cordova, CA | MillingTurningBendingLaserWeldingWaterjetEDMCastingMetal AM | ISO 9001, AS9100, ITAR, CMMC |
| Quantum Machining & Design Inc. Bending, Laser, Welding | Fresno, CA | BendingLaserWelding | - |
| 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 | - |
| RBH Aerospace Inc Milling, Turning, Waterjet, Bending | Lakewood, CA | MillingTurningWaterjetBending | - |
| RivCut Milling, Turning, Bending, Metal AM · ISO 9001, AS9100, ITAR | Union City, CA | MillingTurningBendingMetal AM | ISO 9001, AS9100, ITAR |
| Scotia Engineering, Inc Milling, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Assembly | Santa Fe Springs, CA | MillingWaterjetBendingWeldingStampingEDMGrindingAssembly | - |
| Sharp Dimension Inc Milling, Turning, Bending, Welding, Grinding, Finishing, Assembly · ISO 9001, ITAR | Fremont, CA | MillingTurningBendingWeldingGrindingFinishingAssembly | ISO 9001, ITAR |
| Sheet Metal Specialists (SMS Fabrications, Inc.) Bending, Laser, Welding, Waterjet · ISO 9001 | Riverside, CA | BendingLaserWeldingWaterjet | ISO 9001 |
| Sheetmetal Engineering Inc Milling, Laser, Punching, Bending, Welding · ISO 9001, AS9100 | Simi Valley, CA | MillingLaserPunchingBendingWelding | ISO 9001, AS9100 |
| Steel Werx Bending, Welding | Santa Clara, CA | BendingWelding | - |
| Stockton Tri-Industries, LLC Milling, Turning, Waterjet, Bending, Welding, Assembly | Stockton, CA | MillingTurningWaterjetBendingWeldingAssembly | - |
| T & T Metals Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001 | Covina, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001 |
| Tobar Industries Milling, Turning, Bending, Welding | San Jose, CA | MillingTurningBendingWelding | - |
| Tri Precision Sheetmetal, Inc. Bending, Laser, Welding · ISO 9001, AS9100 | Anaheim, CA | BendingLaserWelding | ISO 9001, AS9100 |
| Trinity Machining, LLC Milling, Turning, Bending, EDM, Grinding, Finishing · ISO 9001 | Grass Valley, CA | MillingTurningBendingEDMGrindingFinishing | ISO 9001 |
| Trio Metal Stamping, Inc Milling, Turning, Laser, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, NADCAP | City Of Industry, CA | MillingTurningLaserBendingWeldingStampingEDMGrinding | ISO 9001, NADCAP |
| Trussworks International Inc Bending, Welding · ISO 9001 | Pomona, CA | BendingWelding | ISO 9001 |
| Valence Precision LLC Milling, Turning, Laser, Waterjet, Bending, Welding, Grinding | Richmond, CA | MillingTurningLaserWaterjetBendingWeldingGrinding | - |
| Verdugo Tool & Engineering Co Inc Laser, Punching, Bending, Stamping, EDM, Grinding, Finishing · ISO 9001, ITAR | Chatsworth, CA | LaserPunchingBendingStampingEDMGrindingFinishing | ISO 9001, ITAR |
| Vinatech Engineering Inc Milling, Laser, Bending, Welding, Assembly · ITAR | San Diego, CA | MillingLaserBendingWeldingAssembly | ITAR |
| Weistec Engineering, Inc Milling, Turning, Laser, Waterjet, Bending, Welding · ISO 9001, AS9100, ITAR | Anaheim, CA | MillingTurningLaserWaterjetBendingWelding | ISO 9001, AS9100, ITAR |
| Weldway Steel Fabrication Inc Turning, Bending, Welding | Oakdale, CA | TurningBendingWelding | - |
| Will-Mann Inc Turning, Laser, Punching, Bending, Welding · ISO 9001, AS9100 | Fullerton, CA | TurningLaserPunchingBendingWelding | ISO 9001, AS9100 |
| Dynamic Loop Inc Milling, Turning, Laser, Waterjet, Finishing | Camarillo, CA | MillingTurningLaserWaterjetFinishing | - |
| GC International Inc Milling, Turning, Welding, Casting, Assembly · AS9100, NADCAP | Camarillo, CA | MillingTurningWeldingCastingAssembly | AS9100, NADCAP |
| Slag Factory Milling, Laser, Welding | Oroville, CA | MillingLaserWelding | - |