| Weldtec Manufacturing, Inc Welding | Waterford, CA | Welding | - |
| US Tower Corp Milling, Welding, Assembly · ISO 9001 | Woodlake, CA | MillingWeldingAssembly | ISO 9001 |
| Walker West LLC Bending, Welding, Stamping, Assembly | Ontario, CA | BendingWeldingStampingAssembly | - |
| 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 | - |
| Wire Works EDM Inc Milling, Turning, Welding, EDM, Assembly · CMMC | Santa Ana, CA | MillingTurningWeldingEDMAssembly | CMMC |
| Will-Mann Inc Turning, Laser, Punching, Bending, Welding · ISO 9001, AS9100 | Fullerton, CA | TurningLaserPunchingBendingWelding | ISO 9001, AS9100 |
| A4 Welding Inc. Welding | Riverside, CA | Welding | - |
| Ace Clearwater Enterprises Inc Milling, Laser, Waterjet, Bending, Welding, Casting | Torrance, CA | MillingLaserWaterjetBendingWeldingCasting | - |
| All-Ways Metal Inc Milling, Turning, Laser, Punching, Bending, Welding, Grinding · ISO 9001, ITAR | Gardena, CA | MillingTurningLaserPunchingBendingWeldingGrinding | ISO 9001, ITAR |
| Antonio's Metal Works, Inc Welding | El Cajon, CA | Welding | - |
| Bob Lewis Machine Company, Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, AS9100 | Gardena, CA | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, AS9100 |
| Bob’s Welding, Machining & Fabrication, Inc. Bending, Welding | Anaheim, CA | BendingWelding | - |
| C & W Manufacturing Milling, Turning, Welding, Grinding, Finishing · ISO 9001, ITAR, CMMC | Turlock, CA | MillingTurningWeldingGrindingFinishing | ISO 9001, ITAR, CMMC |
| CalWest MFG Milling, Turning, Laser, Waterjet, Bending, Welding · ISO 9001, ITAR | Fontana, CA | MillingTurningLaserWaterjetBendingWelding | ISO 9001, ITAR |
| Eastwood Machine, LLC Milling, Turning, Laser, Waterjet, Welding, EDM, Grinding, Finishing, Assembly | Santee, CA | MillingTurningLaserWaterjetWeldingEDMGrindingFinishingAssembly | - |
| Hansens Welding Inc Waterjet, Welding | Gardena, CA | WaterjetWelding | - |
| Heimaster Metal Works Inc Bending, Welding | Lakeside, CA | BendingWelding | - |
| Jerry's Welding & Machine Welding | San Diego, CA | Welding | - |
| Laserworx Mfg Laser, Bending, Welding, Stamping · AS9100, ITAR | Oxnard, CA | LaserBendingWeldingStamping | AS9100, ITAR |
| Machineworks Manufacturing Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001, AS9100, ITAR | Northridge, CA | MillingTurningLaserBendingWeldingFinishing | ISO 9001, AS9100, ITAR |
| Morena Welding Inc Welding | San Diego, CA | Welding | - |
| New World Machining Inc Milling, Turning, Welding | San Jose, CA | MillingTurningWelding | - |
| Nocturnal Welding Welding | Camarillo, CA | Welding | - |
| Powers Bros Machine Inc Welding, Grinding | Montebello, CA | WeldingGrinding | - |
| 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 |
| Snowline Engineering Laser, Waterjet, Welding, Finishing · ISO 9001, AS9100, NADCAP | Cameron Park, CA | LaserWaterjetWeldingFinishing | ISO 9001, AS9100, NADCAP |
| Steel Werx Bending, Welding | Santa Clara, CA | BendingWelding | - |
| Swiss Wire EDM Milling, Turning, Welding, EDM · ISO 9001, ITAR, NADCAP | Costa Mesa, CA | MillingTurningWeldingEDM | ISO 9001, ITAR, NADCAP |
| Trussworks International Inc Bending, Welding · ISO 9001 | Pomona, CA | BendingWelding | ISO 9001 |
| United Western Industries Inc. Milling, Bending, Laser, Welding, Stamping · IATF 16949 | Fresno, CA | MillingBendingLaserWeldingStamping | IATF 16949 |
| Brian's Welding Welding | San Jose, CA | Welding | - |
| Dream Works Metal Bending, Welding | Sacramento, CA | BendingWelding | - |
| J A-Co Machine Works, LLC Milling, Turning, Swiss, Welding, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 | Scotts Valley, CA | MillingTurningSwissWeldingFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 |
| Locdown Com Laser, Bending, Welding, Finishing | Brea, CA | LaserBendingWeldingFinishing | - |
| B & D Precision Welding Milling, Turning, Welding, Grinding | Pomona, CA | MillingTurningWeldingGrinding | - |
| Connelly Machine WKS Milling, Turning, Waterjet, Welding, Grinding · ISO 9001, ITAR | Santa Ana, CA | MillingTurningWaterjetWeldingGrinding | ISO 9001, ITAR |
| Expedite Precision Works Inc Milling, Turning, Swiss, Welding, EDM, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | San Jose, CA | MillingTurningSwissWeldingEDMFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |
| Martin's Metal Fabrication & Welding, Inc Milling, Turning, Laser, Waterjet, Bending, Welding | Vacaville, CA | MillingTurningLaserWaterjetBendingWelding | - |
| Modern Custom Fabrication Welding | Fresno, CA | Welding | - |
| A & A Fabrication and Polishing Corporation Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001, AS9100 | Montebello, CA | MillingTurningLaserPunchingBendingWelding | ISO 9001, AS9100 |
| A&k Manufacturing Inc Turning, Welding, Assembly | Sun Valley, CA | TurningWeldingAssembly | - |
| Abacorp CNC Machined Parts Milling, Turning, Laser, Welding · AS9100 | Moorpark, CA | MillingTurningLaserWelding | AS9100 |
| Abc Sheet Metal Laser, Waterjet, Punching, Bending, Welding · ISO 9001, AS9100 | Anaheim, CA | LaserWaterjetPunchingBendingWelding | ISO 9001, AS9100 |
| Absolute Precision Machining, Inc. Turning, Welding · ISO 9001, AS9100 | Anaheim, CA | TurningWelding | ISO 9001, AS9100 |
| Acc Precision Inc Milling, Turning, Welding, Grinding | Oxnard, CA | MillingTurningWeldingGrinding | - |
| Accurate Metal Products Milling, Punching, Bending, Welding | Jurupa Valley, CA | MillingPunchingBendingWelding | - |
| Advance Metal Products Bending, Welding | Los Angeles, CA | BendingWelding | - |
| Advanced Fabrication Bending, Welding, Waterjet | Bakersfield, CA | BendingWeldingWaterjet | - |