| Peridot Corp Laser, Welding | Pleasanton, CA | LaserWelding | - |
| Pimtad Aerospace LLC Milling, Turning, Swiss, Welding, Grinding, Assembly · AS9100 | Valencia, CA | MillingTurningSwissWeldingGrindingAssembly | AS9100 |
| Premier Steel Bending, Welding | Anaheim, CA | BendingWelding | - |
| Prism Aerospace Bending, Assembly · AS9100, CMMC | Riverside, CA | BendingAssembly | AS9100, CMMC |
| Protool Co Milling, Turning, Swiss · ISO 9001 | Tustin, CA | MillingTurningSwiss | ISO 9001 |
| 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 |
| Pure Source Welding, Finishing | Fontana, CA | WeldingFinishing | - |
| Rache Corp Laser, Welding · ISO 9001, AS9100, ITAR | Camarillo, CA | LaserWelding | ISO 9001, AS9100, ITAR |
| Ramda Metal Specialities Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping · ISO 9001 | Gardena, CA | MillingTurningLaserWaterjetPunchingBendingWeldingStamping | ISO 9001 |
| RivCut Milling, Turning, Bending, Metal AM · ISO 9001, AS9100, ITAR | Union City, CA | MillingTurningBendingMetal AM | ISO 9001, AS9100, ITAR |
| Rivtec LLC Laser, Bending, Welding, Assembly | Santa Ana, CA | LaserBendingWeldingAssembly | - |
| Salsa Prototype Specialties Milling, Turning, Waterjet · ISO 9001 | Ventura, CA | MillingTurningWaterjet | ISO 9001 |
| Slag Factory Milling, Laser, Welding | Oroville, CA | MillingLaserWelding | - |
| Steel Werx Bending, Welding | Santa Clara, CA | BendingWelding | - |
| Superior Pipe Fabricators Welding | Los Angeles, CA | Welding | - |
| Tridecs Corp Milling, Swiss, EDM, Grinding, Finishing, Assembly · ISO 9001 | Hayward, CA | MillingSwissEDMGrindingFinishingAssembly | ISO 9001 |
| US Tower Corp Milling, Welding, Assembly · ISO 9001 | Woodlake, CA | MillingWeldingAssembly | ISO 9001 |
| Wildfactory Milling, Turning, Waterjet | Camarillo, CA | MillingTurningWaterjet | - |
| Dream Works Metal Bending, Welding | Sacramento, CA | BendingWelding | - |
| G2 Metal Fab Bending, Welding | Stockton, CA | BendingWelding | - |