| Elliptical Sheet Metal Mfg LLC Milling, Punching, Bending, Welding | Huntington Beach, CA | MillingPunchingBendingWelding | - |
| A4 Welding Inc. Welding | Riverside, CA | Welding | - |
| Amador Steel and Supply, LLC Milling, Punching, Bending, Welding | Jackson, CA | MillingPunchingBendingWelding | - |
| Bob’s Welding, Machining & Fabrication, Inc. Bending, Welding | Anaheim, CA | BendingWelding | - |
| Campbell Engineering Milling, Welding, EDM, Finishing, Assembly · ISO 9001, ITAR | Lake Forest, CA | MillingWeldingEDMFinishingAssembly | ISO 9001, ITAR |
| Delta Hi-Tech Milling, Turning, Swiss, Laser, Bending, Welding, EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 | Chatsworth, CA | MillingTurningSwissLaserBendingWeldingEDMFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 |
| Delta One Manufacturing LLC Milling, Turning, Laser, Welding, Finishing, Assembly | San Jose, CA | MillingTurningLaserWeldingFinishingAssembly | - |
| deMel Fabrication Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| General Industrial Repair Milling, Turning, Welding, Grinding | Montebello, CA | MillingTurningWeldingGrinding | - |
| Helical Machining, Inc Milling, Turning, Welding, EDM, Grinding, Finishing, Assembly | Sun Valley, CA | MillingTurningWeldingEDMGrindingFinishingAssembly | - |
| Jerry's Welding & Machine Welding | San Diego, CA | Welding | - |
| Kern Steel Fabrication Inc Bending, Welding · ISO 9001 | Bakersfield, CA | BendingWelding | ISO 9001 |
| Melton Sheet Metal Bending, Welding | Fresno, CA | BendingWelding | - |
| Morena Welding Inc Welding | San Diego, CA | Welding | - |
| Nelgo Manufacturing Co Milling, Turning, Punching, Welding · ISO 9001, AS9100, ITAR | Oceanside, CA | MillingTurningPunchingWelding | ISO 9001, AS9100, ITAR |
| Nocturnal Welding Welding | Camarillo, CA | Welding | - |
| Olson & Co. Steel Welding | Fresno, CA | Welding | - |
| Perforated Panels Laser, Waterjet, Bending, Welding | Pacoima, CA | LaserWaterjetBendingWelding | - |
| Premier Steel Bending, Welding | Anaheim, CA | BendingWelding | - |
| Roncelli Plastics Inc Welding, Stamping, Assembly · ISO 9001, ITAR, ISO 13485, CMMC | Monrovia, CA | WeldingStampingAssembly | ISO 9001, ITAR, ISO 13485, CMMC |
| SOS Steel Co Inc Welding | Santa Clara, CA | Welding | - |
| Steel Werx Bending, Welding | Santa Clara, CA | BendingWelding | - |
| Weldtec Manufacturing, Inc Welding | Waterford, CA | Welding | - |
| Weldway Steel Fabrication Inc Turning, Bending, Welding | Oakdale, CA | TurningBendingWelding | - |
| A & A Fabrication and Polishing Corporation Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001, AS9100 | Montebello, CA | MillingTurningLaserPunchingBendingWelding | ISO 9001, AS9100 |
| Antonio's Metal Works, Inc Welding | El Cajon, CA | Welding | - |
| Brian's Welding Welding | San Jose, CA | Welding | - |
| Connelly Machine WKS Milling, Turning, Waterjet, Welding, Grinding · ISO 9001, ITAR | Santa Ana, CA | MillingTurningWaterjetWeldingGrinding | ISO 9001, ITAR |
| Delta Machine Company, LLC Milling, Turning, Welding, Grinding | Harbor City, CA | MillingTurningWeldingGrinding | - |
| Excel Machining Milling, Turning, Bending, Welding, Waterjet · ISO 9001 | Santa Clara, CA | MillingTurningBendingWeldingWaterjet | ISO 9001 |
| Hansens Welding Inc Waterjet, Welding | Gardena, CA | WaterjetWelding | - |
| B & D Precision Welding Milling, Turning, Welding, Grinding | Pomona, CA | MillingTurningWeldingGrinding | - |
| Britech Electropolishing Inc Welding, Finishing | Newark, CA | WeldingFinishing | - |
| California Sheet Metal Bending, Laser, Welding, Waterjet | El Cajon, CA | BendingLaserWeldingWaterjet | - |
| Martin's Metal Fabrication & Welding, Inc Milling, Turning, Laser, Waterjet, Bending, Welding | Vacaville, CA | MillingTurningLaserWaterjetBendingWelding | - |
| Nominal Machining LLC Milling, Turning, Welding · ISO 9001, AS9100, ITAR | Elk Grove, CA | MillingTurningWelding | ISO 9001, AS9100, ITAR |
| Powers Bros Machine Inc Welding, Grinding | Montebello, CA | WeldingGrinding | - |
| Modern Custom Fabrication Welding | Fresno, CA | Welding | - |
| Airtronics Metal Products Milling, Laser, Punching, Bending, Welding, Assembly · ISO 9001, ISO 13485 | Morgan Hill, CA | MillingLaserPunchingBendingWeldingAssembly | ISO 9001, ISO 13485 |
| 6S Machining Enterprises LLC Milling, Welding · ISO 9001, AS9100, ITAR, NADCAP | San Marcos, CA | MillingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| 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 |
| Acc Precision Inc Milling, Turning, Welding, Grinding | Oxnard, CA | MillingTurningWeldingGrinding | - |
| Accurate Metal Products Milling, Punching, Bending, Welding | Jurupa Valley, CA | MillingPunchingBendingWelding | - |
| Ace Clearwater Enterprises Inc Milling, Laser, Waterjet, Bending, Welding, Casting | Torrance, CA | MillingLaserWaterjetBendingWeldingCasting | - |
| Advance Metal Products Bending, Welding | Los Angeles, CA | BendingWelding | - |
| Advanced Fabrication Bending, Welding, Waterjet | Bakersfield, CA | BendingWeldingWaterjet | - |
| Advanced Fabrication Technology Laser, Punching, Welding, Finishing, Assembly · ISO 9001 | Hayward, CA | LaserPunchingWeldingFinishingAssembly | ISO 9001 |
| Advanced Metal Manufacturing Inc Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001, AS9100 | Simi Valley, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001, AS9100 |