| C + C Mfg Milling, Bending, Welding, Grinding, Finishing | Garden City, ID | MillingBendingWeldingGrindingFinishing | - |
| C.E. Machine Company, Inc. Milling, Waterjet, Metal AM · ISO 9001, AS9100 | Wichita, KS | MillingWaterjetMetal AM | ISO 9001, AS9100 |
| C.N.C. Machine Products, Inc Milling, Turning · ISO 9001 | Joplin, MO | MillingTurning | ISO 9001 |
| C.V. Industries Milling, Turning, EDM | Southington, CT | MillingTurningEDM | - |
| C&C Fabrication Co Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Grinding, Finishing, Assembly | Laceys Spring, AL | MillingTurningLaserWaterjetPunchingBendingWeldingGrindingFinishingAssembly | - |
| C2 Machine, LLC Milling, Turning, EDM, Grinding, Assembly | Joelton, TN | MillingTurningEDMGrindingAssembly | - |
| C2 Machining Milling, Welding · ITAR | Kentwood, MI | MillingWelding | ITAR |
| Cal Machine & Manufacturing LLC Milling, Turning, Welding, Assembly · ISO 9001, AS9100 | Chino, CA | MillingTurningWeldingAssembly | ISO 9001, AS9100 |
| Caldwell Corp Milling, Turning, Welding, Grinding | Emporium, PA | MillingTurningWeldingGrinding | - |
| California Lasers Inc Milling, Laser, Welding, EDM, Grinding | Simi Valley, CA | MillingLaserWeldingEDMGrinding | - |
| Calisota Parts, LLC Milling, Waterjet, Stamping, EDM | Frankfort, IL | MillingWaterjetStampingEDM | - |
| Callacore LLC Milling, Turning, Grinding · AS9100 | Hutchinson, KS | MillingTurningGrinding | AS9100 |
| CalWest MFG Milling, Turning, Laser, Waterjet, Bending, Welding · ISO 9001, ITAR | Fontana, CA | MillingTurningLaserWaterjetBendingWelding | ISO 9001, ITAR |
| Camco Manufacturing Inc Milling, Turning, Grinding, Finishing · ISO 9001, AS9100 | Sayre, PA | MillingTurningGrindingFinishing | ISO 9001, AS9100 |
| Camcraft Inc Milling, Turning, Grinding | Hanover Park, IL | MillingTurningGrinding | - |
| Canady Manufacturing Co Inc Milling, Turning, EDM, Grinding · ISO 9001 | San Fernando, CA | MillingTurningEDMGrinding | ISO 9001 |
| Canyon Run Engineering Technologies Milling, Turning, EDM, Grinding, Assembly | Troy, OH | MillingTurningEDMGrindingAssembly | - |
| Caps Machine and Tool, LLC Milling, Turning | Ponder, TX | MillingTurning | - |
| Carlisle Machine Works Inc Milling, Turning, Bending, Welding, EDM, Grinding | Millville, NJ | MillingTurningBendingWeldingEDMGrinding | - |
| Carlson Tool & Manufacturing Corp Milling, Turning, EDM, Grinding | Cedarburg, WI | MillingTurningEDMGrinding | - |
| Carney Mfg LLC Milling | Beaumont, CA | Milling | - |
| Carpatians Manufacturing Corp Milling, Stamping, Finishing, Assembly · ISO 9001, AS9100 | Troy, MI | MillingStampingFinishingAssembly | ISO 9001, AS9100 |
| Carr Machine & Tool, Inc Milling, Grinding, Assembly · ISO 9001, ITAR, CMMC | Elk Grove Village, IL | MillingGrindingAssembly | ISO 9001, ITAR, CMMC |
| Cat-Wood Metalworks Milling, Turning, Assembly · ISO 9001, ITAR | Moraine, OH | MillingTurningAssembly | ISO 9001, ITAR |
| Catamount Machine Works Milling, Turning, EDM · AS9100, ITAR, CMMC | Plant City, FL | MillingTurningEDM | AS9100, ITAR, CMMC |
| CB Manufacturing & Engineering Inc Milling, Turning, EDM · ISO 9001, AS9100 | Santa Ana, CA | MillingTurningEDM | ISO 9001, AS9100 |
| CBM Fabrication Inc Milling, Turning, Waterjet, Welding, EDM, Grinding, Finishing | Ballston Lake, NY | MillingTurningWaterjetWeldingEDMGrindingFinishing | - |
| CCT Enterprises, LLC Milling, Turning, Swiss, Stamping, EDM, Assembly · ISO 9001, AS9100, ITAR, IATF 16949, CMMC | Auburn, IN | MillingTurningSwissStampingEDMAssembly | ISO 9001, AS9100, ITAR, IATF 16949, CMMC |
| Center Tool Co Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Hampshire, IL | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| Centerline Engineered Solutions, Inc Milling, Turning, Laser, Bending, Welding · ISO 9001 | Greenwood, SC | MillingTurningLaserBendingWelding | ISO 9001 |
| Centerline Machine, LLC Milling, Turning, Waterjet, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Waupaca, WI | MillingTurningWaterjetBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| Central Precision Inc Milling, Laser, Punching, Bending, Welding, Grinding, Finishing · ISO 9001 | Boonsboro, MD | MillingLaserPunchingBendingWeldingGrindingFinishing | ISO 9001 |
| Central Valley Machine Inc Milling, Turning, Waterjet, Bending, Welding, EDM · AS9100, ITAR | Logan, UT | MillingTurningWaterjetBendingWeldingEDM | AS9100, ITAR |
| Chesapeake Machine Co Milling, Welding | Baltimore, MD | MillingWelding | - |
| Chicago CNC Machining Co. Milling, Turning, Bending, Welding | Hodgkins, IL | MillingTurningBendingWelding | - |
| Choice Components Milling, Turning, EDM, Grinding · ISO 9001 | Clinton Township, MI | MillingTurningEDMGrinding | ISO 9001 |
| Churchmen's Machine Company Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing | North East, MD | MillingTurningLaserWaterjetWeldingGrindingFinishing | - |
| CJ Manufacturing Milling, Turning, Laser, Finishing | Daytona Beach, FL | MillingTurningLaserFinishing | - |
| CJ Precision Machine Inc Milling, Turning, Welding, Finishing · ISO 9001 | Boise, ID | MillingTurningWeldingFinishing | ISO 9001 |
| Class A Tooling Inc Milling, Turning, Bending, Welding, Stamping, EDM, Grinding | Cabot, AR | MillingTurningBendingWeldingStampingEDMGrinding | - |
| Classic Machine & Engineering Milling, Turning, Laser, Welding, Grinding | Ashland, VA | MillingTurningLaserWeldingGrinding | - |
| Classic Turning Inc Milling, Turning, Swiss, Finishing | Jackson, MI | MillingTurningSwissFinishing | - |
| Cleveland Steel Services LLC Milling, Turning, Grinding | Middleburg Heights, OH | MillingTurningGrinding | - |
| Clinkenbeard & Associates Inc Milling, Casting, Assembly · AS9100, ITAR | South Beloit, IL | MillingCastingAssembly | AS9100, ITAR |
| CM Manufacturing Inc Milling, Turning · ISO 9001, AS9100, ITAR | Missoula, MT | MillingTurning | ISO 9001, AS9100, ITAR |
| CMJ Manufacturing, Inc Milling, Turning, Grinding · AS9100 | Mulvane, KS | MillingTurningGrinding | AS9100 |
| CNC Machining & Engineering Inc Milling, Turning, Swiss | Ontario, CA | MillingTurningSwiss | - |
| CNC Manufacturing Inc Milling, Turning, Swiss, Laser, Grinding · ISO 9001 | Coatesville, PA | MillingTurningSwissLaserGrinding | ISO 9001 |
| CNCEdge Milling, Turning · ISO 9001 | Syracuse, NY | MillingTurning | ISO 9001 |
| Cnspeed Machining LLC Milling, Turning · ITAR | Salisbury, NC | MillingTurning | ITAR |