| Columbia Machine Works, Inc Milling, Turning, Welding, Stamping, Casting · ISO 9001, ITAR | Columbia, TN | MillingTurningWeldingStampingCasting | ISO 9001, ITAR |
| Columbus Machine Works Milling, Turning, Bending, Welding, EDM, Casting | Columbus, OH | MillingTurningBendingWeldingEDMCasting | - |
| Compucraft Fabricators Inc Milling, Turning, Laser, Punching, Bending, Welding, Grinding, Finishing · ISO 9001, ITAR | Montgomeryville, PA | MillingTurningLaserPunchingBendingWeldingGrindingFinishing | ISO 9001, ITAR |
| Connecta Corp Milling, Turning, Swiss | Indianapolis, IN | MillingTurningSwiss | - |
| Conti Tool & Die, Inc Milling, Turning, Bending, Welding, Grinding | Akron, OH | MillingTurningBendingWeldingGrinding | - |
| Continental Machining Co Milling, Turning, Welding, EDM | Albuquerque, NM | MillingTurningWeldingEDM | - |
| Copen Machine, Inc Milling, Turning, Swiss, Welding, Grinding · ISO 9001 | Kent, OH | MillingTurningSwissWeldingGrinding | ISO 9001 |
| Coronado Steel Co Turning, Welding, Casting, Metal AM | Youngstown, OH | TurningWeldingCastingMetal AM | - |
| Courser, Inc Milling, Turning · ISO 9001 | Elmira, NY | MillingTurning | ISO 9001 |
| Cox Machine LLC Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR | Traverse City, MI | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR |
| CPK Manufacturing Milling, Turning, EDM · ISO 9001 | San Jose, CA | MillingTurningEDM | ISO 9001 |
| Craftco Metals Services Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Finishing, Assembly | Sheridan, WY | MillingTurningLaserWaterjetBendingWeldingFinishingAssembly | - |
| Creative Machining Systems Inc Milling, Turning, Welding, EDM, Grinding, Finishing | Trenton, NJ | MillingTurningWeldingEDMGrindingFinishing | - |
| Creed Monarch Milling, Turning, Grinding · ISO 9001 | New Britain, CT | MillingTurningGrinding | ISO 9001 |
| Criterion Manufacturing Turning, Welding | Waterloo, IA | TurningWelding | - |
| Criterion Precision Machining Milling, Turning · ISO 9001, AS9100 | Cleveland, OH | MillingTurning | ISO 9001, AS9100 |
| Critical Components-Oil & Gas Milling, Turning, Welding, Metal AM, Finishing | Oklahoma City, OK | MillingTurningWeldingMetal AMFinishing | - |
| Critical Defense Inc Milling, Turning, Bending, Welding, Grinding, Assembly | Windber, PA | MillingTurningBendingWeldingGrindingAssembly | - |
| CS Precision Manufacturing Inc Turning, Bending, EDM, Finishing · ISO 9001 | Gering, NE | TurningBendingEDMFinishing | ISO 9001 |
| CTC Machining, LLC Milling, Turning | Hampstead, MD | MillingTurning | - |
| Cte Machine Inc Milling, Turning, Finishing | Groveland, FL | MillingTurningFinishing | - |
| Cubitek, Inc Milling, Turning, EDM, Grinding · ISO 9001, AS9100 | Brentwood, NY | MillingTurningEDMGrinding | ISO 9001, AS9100 |
| Cunningham Machine Co Milling, Turning · ISO 9001, AS9100, ITAR | Chelmsford, MA | MillingTurning | ISO 9001, AS9100, ITAR |
| Custom Engineering Co Milling, Turning, Bending, Welding · ISO 9001, ITAR, NADCAP | Erie, PA | MillingTurningBendingWelding | ISO 9001, ITAR, NADCAP |
| Custom Tool & Model Corp Milling, Turning, Laser, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | Frankfort, NY | MillingTurningLaserBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| Cut- Out Creations Milling, Turning, Welding | Rochester, NY | MillingTurningWelding | - |
| Cutco Metal Sawing LLC Milling, Turning, Welding, Grinding | Burleson, TX | MillingTurningWeldingGrinding | - |
| Cyclefab, LLC Milling, Turning, Welding | Renton, WA | MillingTurningWelding | - |
| D & D Design & Manufacturing Inc Milling, Turning, Bending, Laser, Welding | Oklahoma City, OK | MillingTurningBendingLaserWelding | - |
| D-Tek Manufacturing Milling, Turning · ISO 9001, AS9100, ITAR, ISO 13485 | Santa Clara, CA | MillingTurning | ISO 9001, AS9100, ITAR, ISO 13485 |
| D&D Enterprises of Greensboro Inc Milling, Turning, Swiss, Assembly · ISO 9001, AS9100 | Randleman, NC | MillingTurningSwissAssembly | ISO 9001, AS9100 |
| D&J Technologies Inc. Milling, Turning · ISO 9001, AS9100 | Fort Worth, TX | MillingTurning | ISO 9001, AS9100 |
| Daico Precision LLC Milling, Turning, Grinding, Finishing, Assembly | Garden Grove, CA | MillingTurningGrindingFinishingAssembly | - |
| Dalane Machining Inc Turning | Tampa, FL | Turning | - |
| Dallas Precision Machining Milling, Turning, Bending, Laser, Welding, Waterjet, Metal AM · ISO 9001, AS9100, ITAR | Carrollton, TX | MillingTurningBendingLaserWeldingWaterjetMetal AM | ISO 9001, AS9100, ITAR |
| Damco, Inc Milling, Turning, Waterjet, Welding | New Bern, NC | MillingTurningWaterjetWelding | - |
| Dan's Custom Machining LLC Milling, Turning, Welding | Williamsburg, OH | MillingTurningWelding | - |
| Danco Precision, Inc Milling, Turning, Laser, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Phoenixville, PA | MillingTurningLaserWeldingStampingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Dark Threat Fabrication LLC Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001 | Heber Springs, AR | MillingTurningLaserBendingWeldingFinishing | ISO 9001 |
| Davinci Machining Milling, Turning, Swiss | Pinellas Park, FL | MillingTurningSwiss | - |
| Davis Tool Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP | Hillsboro, OR | MillingTurningLaserWaterjetPunchingBendingWeldingEDMGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP |
| DCP Tool Manufacturing, LLC Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Dayton, OH | MillingTurningLaserWeldingEDMGrindingFinishing | - |
| Decker Machine Works Inc Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100, ITAR | Greenfield, MA | MillingTurningSwissEDMGrinding | ISO 9001, AS9100, ITAR |
| Defelice Engineering, Inc Milling, Turning, Bending, Welding, Casting, Grinding | Mooresville, IN | MillingTurningBendingWeldingCastingGrinding | - |
| Deking Precision Inc Turning, Swiss · ISO 9001, AS9100 | Chatsworth, CA | TurningSwiss | ISO 9001, AS9100 |
| Deland Manufacturing Inc Milling, Turning · ISO 9001, AS9100, ITAR | Shelby Township, MI | MillingTurning | ISO 9001, AS9100, ITAR |
| Delco LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100 | Akron, OH | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100 |
| Delt Forge, Inc Milling, Turning, Welding, Forging, Grinding | Rose City, MI | MillingTurningWeldingForgingGrinding | - |
| 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 |
| Deltisan Engineering LLC Milling, Turning, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Parker, CO | MillingTurningPunchingBendingWeldingFinishingAssembly | ISO 9001 |