| Chicago CNC Machining Co. Milling, Turning, Bending, Welding | Hodgkins, IL | MillingTurningBendingWelding | - |
| Chicago Magnesium Casting Co Welding, Casting · AS9100, NADCAP | Blue Island, IL | WeldingCasting | AS9100, NADCAP |
| Chicago Metal Fabricators Bending, Laser, Welding · ISO 9001, ITAR | Chicago, IL | BendingLaserWelding | ISO 9001, ITAR |
| Churchmen's Machine Company Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing | North East, MD | MillingTurningLaserWaterjetWeldingGrindingFinishing | - |
| 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 | - |
| Clark Fixture Technologies Inc Bending, Welding · ISO 9001, AS9100 | Bowling Green, OH | BendingWelding | ISO 9001, AS9100 |
| Clark Machine Corporation Welding, Finishing | Baltimore, MD | WeldingFinishing | - |
| Clark Metal Products Co Milling, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Blairsville, PA | MillingLaserPunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Classic Engineering, LLC Milling, Turning, Waterjet, Welding, Finishing | Gloucester, MA | MillingTurningWaterjetWeldingFinishing | - |
| Clint Precision Manufacturing Milling, Turning, Welding, Waterjet · ISO 9001 | San Diego, CA | MillingTurningWeldingWaterjet | ISO 9001 |
| CM Fabricating Bending, Welding | Kansas City, MO | BendingWelding | - |
| CNC Machine and Fabrication, Inc Laser, Waterjet, Punching, Bending, Welding, Stamping, Grinding, Finishing | Hyde Park, UT | LaserWaterjetPunchingBendingWeldingStampingGrindingFinishing | - |
| CNC Specialties Manufacturing Inc Milling, Turning, Bending, Welding, EDM, Grinding, Finishing | Apollo, PA | MillingTurningBendingWeldingEDMGrindingFinishing | - |
| CNC Syndicate Welding | Ravenswood, WV | Welding | - |
| 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 |
| Coffeyville Sektam, Inc Milling, Turning, Welding, Grinding, Assembly | Coffeyville, KS | MillingTurningWeldingGrindingAssembly | - |
| Colonial Welding, LLC Turning, Laser, Bending, Welding, Finishing | Norfolk, VA | TurningLaserBendingWeldingFinishing | - |
| 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 |
| Comet Fabricating & Welding Co Laser, Bending, Welding | Rockford, IL | LaserBendingWelding | - |
| 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 | - |
| Compco Industries Laser, Welding, Stamping, Finishing · ISO 9001, ITAR | Columbiana, OH | LaserWeldingStampingFinishing | ISO 9001, ITAR |
| Complex Fabricators, Inc. Bending, Laser, Welding, Stamping · AS9100 | Salt Lake City, UT | BendingLaserWeldingStamping | AS9100 |
| Compucraft Fabricators Inc Milling, Turning, Laser, Punching, Bending, Welding, Grinding, Finishing · ISO 9001, ITAR | Montgomeryville, PA | MillingTurningLaserPunchingBendingWeldingGrindingFinishing | ISO 9001, ITAR |
| Compucraft Industries, Inc Waterjet, Punching, Bending, Welding, EDM, Finishing, Assembly · AS9100, NADCAP | Santee, CA | WaterjetPunchingBendingWeldingEDMFinishingAssembly | AS9100, NADCAP |
| Conroe Machine, LLC Milling, Turning, Laser, Bending, Welding, EDM, Grinding, Finishing · ISO 9001 | Conroe, TX | MillingTurningLaserBendingWeldingEDMGrindingFinishing | ISO 9001 |
| Continental Machining Co Milling, Turning, Welding, EDM | Albuquerque, NM | MillingTurningWeldingEDM | - |
| Contract Machining Milling, Turning, Welding · ISO 9001 | Lexington, KY | MillingTurningWelding | ISO 9001 |
| Council Stainless & Sheet Metal Bending, Welding, Waterjet | Oklahoma City, OK | BendingWeldingWaterjet | - |
| Cox Machine LLC Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR | Traverse City, MI | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR |
| CP Industries Inc Milling, Welding, Casting | Granger, IN | MillingWeldingCasting | - |
| Creative Custom Products Milling, Welding | Phoenix, AZ | MillingWelding | - |
| Creative Metal Products Inc Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Neenah, WI | PunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Crown Fabricators Welding | Las Vegas, NV | Welding | - |
| CS Tool Engineering, Inc Milling, Welding | Cedar Springs, MI | MillingWelding | - |
| Csi Manufacturing Inc Milling, Turning, Laser, Welding, Stamping, Finishing · ISO 9001 | Westborough, MA | MillingTurningLaserWeldingStampingFinishing | ISO 9001 |
| Cuevas Machine Co., Inc Welding | Poplarville, MS | Welding | - |
| 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 Laser Works LLC Laser, Bending, Welding | Addison, IL | LaserBendingWelding | - |
| Custom Machine Milling, Turning, Welding, Grinding | Hagerstown, MD | MillingTurningWeldingGrinding | - |
| Custom Machine & Design Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Lincoln, NE | MillingTurningWaterjetWeldingEDMGrinding | - |
| Custom Manufacturing Services, Inc Laser, Welding, Finishing, Assembly · ISO 9001 | Princeton, WV | LaserWeldingFinishingAssembly | ISO 9001 |
| Custom Metal Fabricators Milling, Bending, Laser, Welding | Richmond, VA | MillingBendingLaserWelding | - |
| Custom Metal Works Milling, Bending, Welding | Tulsa, OK | MillingBendingWelding | - |
| Custom Tool & Model Corp Milling, Turning, Laser, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | Frankfort, NY | MillingTurningLaserBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| Cutco Metal Sawing LLC Milling, Turning, Welding, Grinding | Burleson, TX | MillingTurningWeldingGrinding | - |