| Classic Machine & Engineering Milling, Turning, Laser, Welding, Grinding | Ashland, VA | MillingTurningLaserWeldingGrinding | - |
| Classic Turning Inc Milling, Turning, Swiss, Finishing | Jackson, MI | MillingTurningSwissFinishing | - |
| Clay-Groomer Machine Shop, Inc Milling, Turning, Welding | Farmington, NM | MillingTurningWelding | - |
| Clearshot Manufacturing LLC Milling, Swiss, Grinding, Finishing · ISO 9001 | Germantown, WI | MillingSwissGrindingFinishing | ISO 9001 |
| Clint Precision Manufacturing Milling, Turning, Welding, Waterjet · ISO 9001 | San Diego, CA | MillingTurningWeldingWaterjet | ISO 9001 |
| CM Fabrication, LLC Milling, Laser, Welding, Finishing | Sycamore, IL | MillingLaserWeldingFinishing | - |
| 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 | - |
| Coanda Company LLC, the Milling, Turning, Waterjet, Welding · ISO 9001, AS9100 | Shawnee, OK | MillingTurningWaterjetWelding | ISO 9001, AS9100 |
| Coast Aerospace Manufacturing, Inc Milling, Welding · AS9100, ITAR | Placentia, CA | MillingWelding | AS9100, ITAR |
| Cobalt Enterprises LLC Milling, Finishing · ITAR | Arlington, WA | MillingFinishing | ITAR |
| Colbert Manufacturing Co Inc Milling, Turning, Welding, Grinding, Finishing | La Vergne, TN | MillingTurningWeldingGrindingFinishing | - |
| Colleen & Herb Enterprises Inc Milling, Turning, Welding | Fremont, CA | MillingTurningWelding | - |
| Columbia Asc Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM · ISO 9001 | Lawrence, MA | MillingTurningLaserWaterjetBendingWeldingStampingEDM | ISO 9001 |
| Combs Enterprises Incorporated Milling, Turning, Bending, Welding, Finishing · ITAR | Great Mills, MD | MillingTurningBendingWeldingFinishing | ITAR |
| Commercial Metal Fabricators, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding | Dayton, OH | MillingTurningLaserWaterjetPunchingBendingWelding | - |
| Commercial Tool & Die Inc Milling, Turning, Welding, Grinding | Marshall, VA | MillingTurningWeldingGrinding | - |
| Computer Integrated Machining Inc Milling, Turning, Waterjet, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, ITAR | Santee, CA | MillingTurningWaterjetWeldingStampingEDMGrindingAssembly | ISO 9001, ITAR |
| Concise Manufacturing Inc Milling, Turning, Welding, EDM | Salisbury, NC | MillingTurningWeldingEDM | - |
| Connecta Corp Milling, Turning, Swiss | Indianapolis, IN | MillingTurningSwiss | - |
| 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 | - |
| Covert Manufacturing, Inc Milling, Turning, Welding, Grinding · ISO 9001, ITAR, IATF 16949 | Galion, OH | MillingTurningWeldingGrinding | ISO 9001, ITAR, IATF 16949 |
| Cox Machine LLC Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR | Traverse City, MI | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR |
| 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 | - |
| Craftco Metals Services Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Finishing, Assembly | Sheridan, WY | MillingTurningLaserWaterjetBendingWeldingFinishingAssembly | - |
| Creative Custom Products Milling, Welding | Phoenix, AZ | MillingWelding | - |
| Critical Components-Oil & Gas Milling, Turning, Welding, Metal AM, Finishing | Oklahoma City, OK | MillingTurningWeldingMetal AMFinishing | - |
| Crucial Component Machining LLC Milling, Turning, Swiss, EDM | Concord, NH | MillingTurningSwissEDM | - |
| Crucial Gear LLC Milling, Welding | Uintah, UT | MillingWelding | - |
| Cte Machine Inc Milling, Turning, Finishing | Groveland, FL | MillingTurningFinishing | - |
| Cuddeback Machining, Inc Milling, Turning, Laser, Welding, Stamping, EDM, Grinding · ISO 9001 | Hilton, NY | MillingTurningLaserWeldingStampingEDMGrinding | ISO 9001 |
| Cumberland Machine Co Milling, Turning, Welding | Nashville, TN | MillingTurningWelding | - |
| Custom Aerospace Milling, Turning, Welding, EDM, Finishing, Assembly | Palm Bay, FL | MillingTurningWeldingEDMFinishingAssembly | - |
| 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 Materials Inc Milling, Welding, Stamping, Grinding, Assembly · ISO 9001 | Chagrin Falls, OH | MillingWeldingStampingGrindingAssembly | ISO 9001 |
| Custom Tool & Model Corp Milling, Turning, Laser, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | Frankfort, NY | MillingTurningLaserBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| Custom Tool Inc Milling, Swiss · ISO 9001 | Cookeville, TN | MillingSwiss | ISO 9001 |
| Cutting Edge Fabrication Inc Milling, Bending, Laser, Welding · ISO 9001 | Milwaukee, WI | MillingBendingLaserWelding | ISO 9001 |
| Cutting Edge Manufacturing Milling, Bending, Welding · ISO 9001, AS9100 | Caldwell, ID | MillingBendingWelding | ISO 9001, AS9100 |
| Cutting Source Precision Milling, Turning, Bending, Welding, EDM, Stamping · ISO 9001 | Houston, TX | MillingTurningBendingWeldingEDMStamping | ISO 9001 |