| Concise Manufacturing Inc Milling, Turning, Welding, EDM | Salisbury, NC | MillingTurningWeldingEDM | - |
| Connecta Corp Milling, Turning, Swiss | Indianapolis, IN | MillingTurningSwiss | - |
| Connelly Machine WKS Milling, Turning, Waterjet, Welding, Grinding · ISO 9001, ITAR | Santa Ana, CA | MillingTurningWaterjetWeldingGrinding | ISO 9001, ITAR |
| 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 |
| Consolidated Metal Products Milling, Turning, Bending, Laser, Welding, Stamping · ISO 9001 | Grand Rapids, MI | MillingTurningBendingLaserWeldingStamping | ISO 9001 |
| Conti Tool & Die, Inc Milling, Turning, Bending, Welding, Grinding | Akron, OH | MillingTurningBendingWeldingGrinding | - |
| Continental Machining Co Milling, Turning, Welding, EDM | Albuquerque, NM | MillingTurningWeldingEDM | - |
| Contract Machining Milling, Turning, Welding · ISO 9001 | Lexington, KY | MillingTurningWelding | ISO 9001 |
| Conturo Prototyping, LLC Milling, Turning | Pittsburgh, PA | MillingTurning | - |
| 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 | - |
| Cortec Precision Sheetmetal Milling, Turning, Bending, Laser, Welding | San Jose, CA | MillingTurningBendingLaserWelding | - |
| 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 |
| Crater Industries LLC Milling, Turning, EDM, Grinding, Assembly | Santa Clarita, CA | MillingTurningEDMGrindingAssembly | - |
| Creative Machining Systems Inc Milling, Turning, Welding, EDM, Grinding, Finishing | Trenton, NJ | MillingTurningWeldingEDMGrindingFinishing | - |
| Criterion Manufacturing Turning, Welding | Waterloo, IA | TurningWelding | - |
| Criterion Precision Machining Milling, Turning · ISO 9001, AS9100 | Cleveland, OH | MillingTurning | ISO 9001, AS9100 |
| Critical Defense Inc Milling, Turning, Bending, Welding, Grinding, Assembly | Windber, PA | MillingTurningBendingWeldingGrindingAssembly | - |
| Crowdynamics LLC Milling, Turning, Finishing, Assembly | Albuquerque, NM | MillingTurningFinishingAssembly | - |
| Crown Machine Inc Milling, Turning, Welding, EDM · ISO 9001 | Rockford, IL | MillingTurningWeldingEDM | ISO 9001 |
| Crucial Component Machining LLC Milling, Turning, Swiss, EDM | Concord, NH | MillingTurningSwissEDM | - |
| 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 |
| Cuddeback Machining, Inc Milling, Turning, Laser, Welding, Stamping, EDM, Grinding · ISO 9001 | Hilton, NY | MillingTurningLaserWeldingStampingEDMGrinding | ISO 9001 |
| Cunningham Machine Co Milling, Turning · ISO 9001, AS9100, ITAR | Chelmsford, MA | MillingTurning | ISO 9001, AS9100, ITAR |
| Curry Precision Machining LLC Milling, Turning | Winchester, CA | MillingTurning | - |
| Custom Machine Milling, Turning, Welding, Grinding | Hagerstown, MD | MillingTurningWeldingGrinding | - |
| Custom Machine & Design Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Lincoln, NE | MillingTurningWaterjetWeldingEDMGrinding | - |
| Custom Machine Works LLC Milling, Turning, Stamping, Grinding | Fenton, MO | MillingTurningStampingGrinding | - |
| Custom Tooling Co Milling, Turning | Cincinnati, OH | MillingTurning | - |
| Cut- Out Creations Milling, Turning, Welding | Rochester, NY | MillingTurningWelding | - |
| Cutco Metal Sawing LLC Milling, Turning, Welding, Grinding | Burleson, TX | MillingTurningWeldingGrinding | - |
| Cutter Innovations, LLC Milling, Turning, EDM · AS9100 | Wheat Ridge, CO | MillingTurningEDM | AS9100 |
| Cutting Solutions Turning, Laser, Waterjet, Bending, Welding, Grinding, Finishing, Assembly | Zeeland, MI | TurningLaserWaterjetBendingWeldingGrindingFinishingAssembly | - |
| Cutting Source Precision Milling, Turning, Bending, Welding, EDM, Stamping · ISO 9001 | Houston, TX | MillingTurningBendingWeldingEDMStamping | ISO 9001 |
| CV International, Inc Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001 | Bend, OR | MillingTurningLaserPunchingBendingWelding | ISO 9001 |
| D & D Automation Inc Milling, Turning, Welding, EDM | Terre Haute, IN | MillingTurningWeldingEDM | - |
| 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 & S Manufacturing, Inc Milling, Turning, Assembly · ISO 9001, ITAR | Wichita, KS | MillingTurningAssembly | ISO 9001, ITAR |
| D&D Enterprises of Greensboro Inc Milling, Turning, Swiss, Assembly · ISO 9001, AS9100 | Randleman, NC | MillingTurningSwissAssembly | ISO 9001, AS9100 |
| D&e Machining Milling, Turning | Corry, PA | MillingTurning | - |
| D&F Screw Machine Products Turning, Waterjet, Grinding · ISO 9001 | East Hanover, NJ | TurningWaterjetGrinding | ISO 9001 |