| Computer Integrated Machining Inc Milling, Turning, Waterjet, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, ITAR | Santee, CA | MillingTurningWaterjetWeldingStampingEDMGrindingAssembly | ISO 9001, ITAR |
| 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 |
| Container Products Company, LLC Welding | Currie, NC | Welding | - |
| 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 Manufacturing Co Milling, Turning, Swiss, EDM · ISO 9001, ITAR | San Antonio, TX | MillingTurningSwissEDM | ISO 9001, ITAR |
| Criterion Manufacturing Turning, Welding | Waterloo, IA | TurningWelding | - |
| Critical Components-Oil & Gas Milling, Turning, Welding, Metal AM, Finishing | Oklahoma City, OK | MillingTurningWeldingMetal AMFinishing | - |
| CTC Machining, LLC Milling, Turning | Hampstead, MD | MillingTurning | - |
| Cubitek, Inc Milling, Turning, EDM, Grinding · ISO 9001, AS9100 | Brentwood, NY | MillingTurningEDMGrinding | ISO 9001, AS9100 |
| Cuevas Machine Co., Inc Welding | Poplarville, MS | Welding | - |
| Cumberland Machine Co Milling, Turning, Welding | Nashville, TN | MillingTurningWelding | - |
| Cunningham Machine Co Milling, Turning · ISO 9001, AS9100, ITAR | Chelmsford, MA | MillingTurning | ISO 9001, AS9100, ITAR |
| 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 & Welding, Inc Turning, Waterjet, Bending, Welding, Grinding, Finishing | North Augusta, SC | TurningWaterjetBendingWeldingGrindingFinishing | - |
| Custom Manufacturing Services, Inc Laser, Welding, Finishing, Assembly · ISO 9001 | Princeton, WV | LaserWeldingFinishingAssembly | ISO 9001 |
| Cutting Solutions Turning, Laser, Waterjet, Bending, Welding, Grinding, Finishing, Assembly | Zeeland, MI | TurningLaserWaterjetBendingWeldingGrindingFinishingAssembly | - |
| CV International, Inc Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001 | Bend, OR | MillingTurningLaserPunchingBendingWelding | ISO 9001 |
| D & D Manufacturing LLC Milling, Turning, Grinding | Ipswich, MA | MillingTurningGrinding | - |
| D & H Engineering Inc Milling, EDM · AS9100 | Camarillo, CA | MillingEDM | AS9100 |
| Dahlgren Technologies LLC Welding | King George, VA | Welding | - |
| Dalton Manufacturing Group Inc Milling, Turning, Grinding · ISO 9001, CMMC | Amesbury, MA | MillingTurningGrinding | ISO 9001, CMMC |
| Dark Threat Fabrication LLC Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001 | Heber Springs, AR | MillingTurningLaserBendingWeldingFinishing | ISO 9001 |
| Davis Manufacturing Co Milling, Turning, Welding, Finishing · AS9100, ITAR, CMMC | Wheat Ridge, CO | MillingTurningWeldingFinishing | AS9100, ITAR, CMMC |
| DCP Tool Manufacturing, LLC Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Dayton, OH | MillingTurningLaserWeldingEDMGrindingFinishing | - |
| Defiant CNC Milling, Turning | Orlando, FL | MillingTurning | - |
| Delaware Metals Milling, Turning, EDM | Wilmington, DE | MillingTurningEDM | - |
| Delflo Industries Inc Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR, ISO 13485, CMMC | Delray Beach, FL | MillingTurningWaterjetBendingWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR, ISO 13485, CMMC |
| Delta Hi-Tech Milling, Turning, Swiss, Laser, Bending, Welding, EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 | Chatsworth, CA | MillingTurningSwissLaserBendingWeldingEDMFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 |
| Delta Machining Inc Milling, Turning, Welding, Grinding · ISO 9001 | Niles, MI | MillingTurningWeldingGrinding | ISO 9001 |
| Delta One Manufacturing LLC Milling, Turning, Laser, Welding, Finishing, Assembly | San Jose, CA | MillingTurningLaserWeldingFinishingAssembly | - |
| Delta V LLC Milling · ISO 9001 | Sanford, FL | Milling | ISO 9001 |
| Denali MetalWorks Bending, Laser, Welding, Waterjet | Phoenix, AZ | BendingLaserWeldingWaterjet | - |
| Derecktor Marine Technology LLC Milling, Turning, Waterjet, Welding | Bristol, RI | MillingTurningWaterjetWelding | - |
| Deweys Service Company, LLC Laser, Welding, Grinding | Columbia, SC | LaserWeldingGrinding | - |
| DGF Industrial Innovations Group, Ltd Milling, Turning, Bending, Welding · ISO 9001 | Gilford, NH | MillingTurningBendingWelding | ISO 9001 |
| Diamond Manufacturing of Bluffton, Ltd Laser, Welding, Assembly | Bluffton, OH | LaserWeldingAssembly | - |
| Die & Tool Service, Inc Milling, Stamping, EDM | Sugar Land, TX | MillingStampingEDM | - |
| Die Craft Milling, Turning, Welding, Waterjet · ISO 9001 | Cincinnati, OH | MillingTurningWeldingWaterjet | ISO 9001 |
| Die Technology, Inc Milling, Turning, Swiss, Bending, Stamping, EDM, Grinding · ISO 9001, CMMC | Saint Michael, MN | MillingTurningSwissBendingStampingEDMGrinding | ISO 9001, CMMC |
| Diversitech Inc Milling, Turning, Assembly · ISO 9001 | Riverdale, NJ | MillingTurningAssembly | ISO 9001 |
| Dixie Metalcraft Corp Bending · ISO 9001 | Hazel Green, AL | Bending | ISO 9001 |
| Dixie Rubber & Plastics Inc Milling, Waterjet, Grinding | Greenville, SC | MillingWaterjetGrinding | - |
| Dolphin Manufacturing, Inc Milling, Turning, Finishing, Assembly · ISO 9001 | Taylor, MI | MillingTurningFinishingAssembly | ISO 9001 |
| Donahue Industries, Incorporated Milling, Turning, Swiss, Punching, Bending, Welding, Stamping, EDM, Grinding, Finishing | Shrewsbury, MA | MillingTurningSwissPunchingBendingWeldingStampingEDMGrindingFinishing | - |
| Dothan Steel Fabricators, LLC Welding | Dothan, AL | Welding | - |
| DP Products, Inc Milling, Turning, EDM · ISO 9001 | San Jose, CA | MillingTurningEDM | ISO 9001 |