| Columbia Machine Works, Inc Milling, Turning, Welding, Stamping, Casting · ISO 9001, ITAR | Columbia, TN | MillingTurningWeldingStampingCasting | ISO 9001, ITAR |
| Commercial Tool & Die Inc Milling, Turning, Welding, Grinding | Marshall, VA | MillingTurningWeldingGrinding | - |
| Competitive Engineering, Inc Milling, Turning, EDM, Grinding, Assembly · AS9100 | Tucson, AZ | MillingTurningEDMGrindingAssembly | AS9100 |
| Concise Manufacturing Inc Milling, Turning, Welding, EDM | Salisbury, NC | MillingTurningWeldingEDM | - |
| Conner Brothers Machine Co., Inc Milling, Turning, Welding, Grinding · ISO 9001 | Bessemer City, NC | MillingTurningWeldingGrinding | ISO 9001 |
| Conroe Machine, LLC Milling, Turning, Laser, Bending, Welding, EDM, Grinding, Finishing · ISO 9001 | Conroe, TX | MillingTurningLaserBendingWeldingEDMGrindingFinishing | ISO 9001 |
| Conti Tool & Die, Inc Milling, Turning, Bending, Welding, Grinding | Akron, OH | MillingTurningBendingWeldingGrinding | - |
| Continental Machining Co Milling, Turning, Welding, EDM | Albuquerque, NM | MillingTurningWeldingEDM | - |
| Cope Plastics, Inc Turning, Bending | Fargo, ND | TurningBending | - |
| Corestar International Corporation Milling, Turning | Irwin, PA | MillingTurning | - |
| Courser, Inc Milling, Turning · ISO 9001 | Elmira, NY | MillingTurning | ISO 9001 |
| Covert Manufacturing, Inc Milling, Turning, Welding, Grinding · ISO 9001, ITAR, IATF 16949 | Galion, OH | MillingTurningWeldingGrinding | ISO 9001, ITAR, IATF 16949 |
| Cox Manufacturing Co Milling, Turning, Swiss, EDM · ISO 9001, ITAR | San Antonio, TX | MillingTurningSwissEDM | 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 |
| Crown Machine Inc Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| CS Precision Manufacturing Inc Turning, Bending, EDM, Finishing · ISO 9001 | Gering, NE | TurningBendingEDMFinishing | ISO 9001 |
| Csi Manufacturing Inc Milling, Turning, Laser, Welding, Stamping, Finishing · ISO 9001 | Westborough, MA | MillingTurningLaserWeldingStampingFinishing | ISO 9001 |
| Cumberland Machine Co Milling, Turning, Welding | Nashville, TN | MillingTurningWelding | - |
| Custom Engineering Co Milling, Turning, Bending, Welding · ISO 9001, ITAR, NADCAP | Erie, PA | MillingTurningBendingWelding | ISO 9001, ITAR, NADCAP |
| Custom Machine Milling, Turning, Welding, Grinding | Hagerstown, MD | MillingTurningWeldingGrinding | - |
| Custom Machine & Design Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Lincoln, NE | MillingTurningWaterjetWeldingEDMGrinding | - |
| Custom Machine & Welding, Inc Turning, Waterjet, Bending, Welding, Grinding, Finishing | North Augusta, SC | TurningWaterjetBendingWeldingGrindingFinishing | - |
| Custom Machine Inc Milling, Turning, EDM · ISO 9001, AS9100, ITAR, ISO 13485, NADCAP | Woburn, MA | MillingTurningEDM | ISO 9001, AS9100, ITAR, ISO 13485, 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 | - |
| Cutter Innovations, LLC Milling, Turning, EDM · AS9100 | Wheat Ridge, CO | MillingTurningEDM | AS9100 |
| Cutting Edge Manufacturing Milling, Turning, Assembly · ISO 9001, AS9100 | Newbury Park, CA | MillingTurningAssembly | ISO 9001, AS9100 |
| CV International, Inc Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001 | Bend, OR | MillingTurningLaserPunchingBendingWelding | ISO 9001 |
| Cyclefab, LLC Milling, Turning, Welding | Renton, WA | MillingTurningWelding | - |
| D & D Design & Manufacturing Inc Milling, Turning, Bending, Laser, Welding | Oklahoma City, OK | MillingTurningBendingLaserWelding | - |
| D & D Manufacturing LLC Milling, Turning, Grinding | Ipswich, MA | MillingTurningGrinding | - |
| D & G Machine Products, LLC Milling, Turning, Bending, Laser, Welding · ISO 9001, AS9100 | Gorham, ME | MillingTurningBendingLaserWelding | ISO 9001, AS9100 |
| D & H Industries Inc Milling, Turning, Laser, Bending, Welding, Stamping, Grinding, Finishing · ISO 9001, ITAR | Oconomowoc, WI | MillingTurningLaserBendingWeldingStampingGrindingFinishing | ISO 9001, ITAR |
| D & S Machine Service Inc Milling, Turning, Welding · ISO 9001 | Luxemburg, WI | MillingTurningWelding | ISO 9001 |
| D-Tek Manufacturing Milling, Turning · ISO 9001, AS9100, ITAR, ISO 13485 | Santa Clara, CA | MillingTurning | ISO 9001, AS9100, ITAR, ISO 13485 |
| D&e Machining Milling, Turning | Corry, PA | MillingTurning | - |
| Dalane Machining Inc Turning | Tampa, FL | Turning | - |
| Dalton Manufacturing Group Inc Milling, Turning, Grinding · ISO 9001, CMMC | Amesbury, MA | MillingTurningGrinding | ISO 9001, CMMC |
| Davis Tool & Die, Inc Milling, Turning, Welding, Stamping, EDM, Grinding | Abbeville, MS | MillingTurningWeldingStampingEDMGrinding | - |
| 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 |
| Davlan Engineering Inc Milling, Turning, Laser, Welding, Stamping | Saint Louis, MO | MillingTurningLaserWeldingStamping | - |
| DCP Tool Manufacturing, LLC Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Dayton, OH | MillingTurningLaserWeldingEDMGrindingFinishing | - |
| Dechert Dynamics Corp Milling, Turning, Welding, Grinding · ISO 9001 | Palmyra, PA | MillingTurningWeldingGrinding | ISO 9001 |
| Defelice Engineering, Inc Milling, Turning, Bending, Welding, Casting, Grinding | Mooresville, IN | MillingTurningBendingWeldingCastingGrinding | - |
| Defiant CNC Milling, Turning | Orlando, FL | MillingTurning | - |
| 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 |