| Stellar Engineering Milling, Turning · AS9100 | Anaheim, CA | MillingTurning | AS9100 |
| Suntiger Industries LLC Welding · ISO 9001, AS9100, ITAR | Oceanside, CA | Welding | ISO 9001, AS9100, ITAR |
| Superior Jig Inc Milling, EDM · ISO 9001, ITAR | Anaheim, CA | MillingEDM | ISO 9001, ITAR |
| Swiss Wire EDM Milling, Turning, Welding, EDM · ISO 9001, ITAR, NADCAP | Costa Mesa, CA | MillingTurningWeldingEDM | ISO 9001, ITAR, NADCAP |
| T & T Metals Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001 | Covina, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001 |
| T&K Machine Milling, Turning, Welding, EDM, Grinding | Livermore, CA | MillingTurningWeldingEDMGrinding | - |
| TDC Manufacturing Inc Milling, Turning, Laser | Redlands, CA | MillingTurningLaser | - |
| The Champ Company Welding, Assembly | Campbell, CA | WeldingAssembly | - |
| ThermoAir Grinding | Burbank, CA | Grinding | - |
| TJ Aerospace Inc Milling, Assembly | Garden Grove, CA | MillingAssembly | - |
| Tobar Industries Milling, Turning, Bending, Welding | San Jose, CA | MillingTurningBendingWelding | - |
| Tomi Engineering, Inc Milling · ISO 9001, AS9100, ITAR | Santa Ana, CA | Milling | ISO 9001, AS9100, ITAR |
| Topnotch Quality Works Milling, Turning · ISO 9001, ITAR | Pacoima, CA | MillingTurning | ISO 9001, ITAR |
| Total Concept Enterprises, Inc. Milling, Turning, Bending, Welding | Fresno, CA | MillingTurningBendingWelding | - |
| Trabuco Precision LLC Milling, Turning, Grinding · ISO 9001, AS9100 | Yorba Linda, CA | MillingTurningGrinding | ISO 9001, AS9100 |
| 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 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 |
| Udash Corporation Milling, Laser, Waterjet, Welding, Stamping, Assembly · ISO 9001, AS9100 | Simi Valley, CA | MillingLaserWaterjetWeldingStampingAssembly | ISO 9001, AS9100 |
| United Western Industries Inc. Milling, Bending, Laser, Welding, Stamping · IATF 16949 | Fresno, CA | MillingBendingLaserWeldingStamping | IATF 16949 |
| Upland Fab Inc Milling, Turning · ISO 9001, AS9100, ITAR | Ontario, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| US Precision Sheet Metal, Inc Milling, Laser, Punching, Welding, Assembly | Riverside, CA | MillingLaserPunchingWeldingAssembly | - |
| US Tower Corp Milling, Welding, Assembly · ISO 9001 | Woodlake, CA | MillingWeldingAssembly | ISO 9001 |
| V&S Engineering Milling, Turning, EDM, Grinding · ISO 9001, AS9100, ITAR | Huntington Beach, CA | MillingTurningEDMGrinding | ISO 9001, AS9100, ITAR |
| Van's Manufacturing, Inc Milling, Turning | Simi Valley, CA | MillingTurning | - |
| Veco Technologies, Inc. Milling, Turning, Welding, EDM | Fresno, CA | MillingTurningWeldingEDM | - |
| 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 |
| Vinatech Engineering Inc Milling, Laser, Bending, Welding, Assembly · ITAR | San Diego, CA | MillingLaserBendingWeldingAssembly | ITAR |
| Vista Industries, Inc Welding, Finishing | Palmdale, CA | WeldingFinishing | - |
| W Machine Works Inc Milling, Turning, Assembly · ISO 9001, AS9100, ITAR | San Fernando, CA | MillingTurningAssembly | ISO 9001, AS9100, ITAR |
| 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 |
| Weldtec Manufacturing, Inc Welding | Waterford, CA | Welding | - |
| Westcoast Precision, Inc Milling, Turning, Assembly · ISO 9001, AS9100, ITAR | San Jose, CA | MillingTurningAssembly | ISO 9001, AS9100, ITAR |
| Wildfactory Milling, Turning, Waterjet | Camarillo, CA | MillingTurningWaterjet | - |
| Yuhas Tooling & Machining Inc Milling, Turning, Grinding, Finishing | Milpitas, CA | MillingTurningGrindingFinishing | - |
| ZI Machine Milling, Turning · ISO 9001, AS9100, ITAR | El Dorado Hills, CA | MillingTurning | ISO 9001, AS9100, ITAR |