| CJ Precision Machine Inc Milling, Turning, Welding, Finishing · ISO 9001 | Boise, ID | MillingTurningWeldingFinishing | ISO 9001 |
| Clardy Machine Works LLC Milling, Turning, Welding | Bremen, KY | MillingTurningWelding | - |
| Class A Tooling Inc Milling, Turning, Bending, Welding, Stamping, EDM, Grinding | Cabot, AR | MillingTurningBendingWeldingStampingEDMGrinding | - |
| Classic Engineering, LLC Milling, Turning, Waterjet, Welding, Finishing | Gloucester, MA | MillingTurningWaterjetWeldingFinishing | - |
| Classic Machine & Engineering Milling, Turning, Laser, Welding, Grinding | Ashland, VA | MillingTurningLaserWeldingGrinding | - |
| Classic Turning Inc Milling, Turning, Swiss, Finishing | Jackson, MI | MillingTurningSwissFinishing | - |
| Clearwater Machining Inc Milling, Turning | Clearwater, FL | MillingTurning | - |
| Clinkenbeard & Associates Inc Milling, Casting, Assembly · AS9100, ITAR | South Beloit, IL | MillingCastingAssembly | AS9100, ITAR |
| Clint Precision Manufacturing Milling, Turning, Welding, Waterjet · ISO 9001 | San Diego, CA | MillingTurningWeldingWaterjet | ISO 9001 |
| CM Manufacturing Inc Milling, Turning · ISO 9001, AS9100, ITAR | Missoula, MT | MillingTurning | ISO 9001, AS9100, ITAR |
| CNC Industries, LLC Milling, Turning, Finishing, Assembly · ISO 9001, AS9100, ITAR | Fort Wayne, IN | MillingTurningFinishingAssembly | ISO 9001, AS9100, ITAR |
| CNC Innotech LLC Milling, Turning, Swiss | Ogdensburg, NJ | MillingTurningSwiss | - |
| CNC Machining & Engineering Inc Milling, Turning, Swiss | Ontario, CA | MillingTurningSwiss | - |
| CNC Manufacturing Corp Milling, Turning, Swiss · ISO 9001, AS9100 | Long Is City, NY | MillingTurningSwiss | ISO 9001, AS9100 |
| CNC Manufacturing Inc Milling, Turning, Swiss, Laser, Grinding · ISO 9001 | Coatesville, PA | MillingTurningSwissLaserGrinding | ISO 9001 |
| CNC Specialties Manufacturing Inc Milling, Turning, Bending, Welding, EDM, Grinding, Finishing | Apollo, PA | MillingTurningBendingWeldingEDMGrindingFinishing | - |
| CNCEdge Milling, Turning · ISO 9001 | Syracuse, NY | MillingTurning | ISO 9001 |
| Cnspeed Machining LLC Milling, Turning · ITAR | Salisbury, NC | MillingTurning | ITAR |
| Coanda Company LLC, the Milling, Turning, Waterjet, Welding · ISO 9001, AS9100 | Shawnee, OK | MillingTurningWaterjetWelding | ISO 9001, AS9100 |
| Coast Precision Enterprises Milling, Turning · ISO 9001, AS9100, ITAR | San Diego, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| Coastal Machine & Supply Inc Milling, Turning · ISO 9001, AS9100, ITAR, CMMC | Carencro, LA | MillingTurning | ISO 9001, AS9100, ITAR, CMMC |
| Cobalt Enterprises LLC Milling, Finishing · ITAR | Arlington, WA | MillingFinishing | ITAR |
| Colburn Manufacturing Company Milling, Turning · ISO 9001, ISO 13485 | Fridley, MN | MillingTurning | ISO 9001, ISO 13485 |
| Colleen & Herb Enterprises Inc Milling, Turning, Welding | Fremont, CA | MillingTurningWelding | - |
| Collins Custom Manufacturing LLC Milling · ISO 9001, ITAR | Fort Worth, TX | Milling | ISO 9001, ITAR |
| Collins Manufacturing Inc Milling, Turning, EDM · ITAR | Essex, MA | MillingTurningEDM | ITAR |
| Colorado Machine Works, Inc. Milling, Turning | Colorado Springs, CO | MillingTurning | - |
| Columbus Machine Works Milling, Turning, Bending, Welding, EDM, Casting | Columbus, OH | MillingTurningBendingWeldingEDMCasting | - |
| Combs Enterprises Incorporated Milling, Turning, Bending, Welding, Finishing · ITAR | Great Mills, MD | MillingTurningBendingWeldingFinishing | ITAR |
| Commercial Tool & Die Inc Milling, Turning, Welding, Grinding | Marshall, VA | MillingTurningWeldingGrinding | - |
| Compass Machine & Inspection LLC Milling | Houston, TX | Milling | - |
| 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 |
| 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 |
| CP Industries Inc Milling, Welding, Casting | Granger, IN | MillingWeldingCasting | - |
| 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 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 | - |