| 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 Manufacturing & Polishing Inc Waterjet, Welding | Springfield, MO | WaterjetWelding | - |
| Custom Manufacturing Co Bending, Laser, Welding, Stamping · ISO 9001 | Dallas, TX | BendingLaserWeldingStamping | ISO 9001 |
| 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 Fabrication LLC Welding | Tucson, AZ | Welding | - |
| Cutting Edge Manufacturing Milling, Bending, Welding · ISO 9001, AS9100 | Caldwell, ID | MillingBendingWelding | ISO 9001, AS9100 |
| Cutting Solutions Turning, Laser, Waterjet, Bending, Welding, Grinding, Finishing, Assembly | Zeeland, MI | TurningLaserWaterjetBendingWeldingGrindingFinishingAssembly | - |
| Cutting Source Precision Milling, Turning, Bending, Welding, EDM, Stamping · ISO 9001 | Houston, TX | MillingTurningBendingWeldingEDMStamping | ISO 9001 |
| CV International, Inc Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001 | Bend, OR | MillingTurningLaserPunchingBendingWelding | ISO 9001 |
| Cyclefab, LLC Milling, Turning, Welding | Renton, WA | MillingTurningWelding | - |
| D & D Automation Inc Milling, Turning, Welding, EDM | Terre Haute, IN | MillingTurningWeldingEDM | - |
| D & D Design & Manufacturing Inc Milling, Turning, Bending, Laser, Welding | Oklahoma City, OK | MillingTurningBendingLaserWelding | - |
| D & G Machine Products, LLC Milling, Turning, Bending, Laser, Welding · ISO 9001, AS9100 | Gorham, ME | MillingTurningBendingLaserWelding | ISO 9001, AS9100 |
| D & G Manufacturing LLC Milling, Turning, Welding | Aurora, CO | MillingTurningWelding | - |
| D & H Industries Inc Milling, Turning, Laser, Bending, Welding, Stamping, Grinding, Finishing · ISO 9001, ITAR | Oconomowoc, WI | MillingTurningLaserBendingWeldingStampingGrindingFinishing | ISO 9001, ITAR |
| D & S Machine Service Inc Milling, Turning, Welding · ISO 9001 | Luxemburg, WI | MillingTurningWelding | ISO 9001 |
| D. J. Fabricators, Inc Milling, Laser, Waterjet, Punching, Bending, Welding, EDM, Grinding, Assembly · ISO 9001 | Ipswich, MA | MillingLaserWaterjetPunchingBendingWeldingEDMGrindingAssembly | ISO 9001 |
| D.P. Tool Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Avon, NY | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Dacval, LLC Welding, Finishing · ISO 9001, AS9100, ITAR | Philadelphia, PA | WeldingFinishing | ISO 9001, AS9100, ITAR |
| DAD Manufacturing, Inc. Bending, Welding · ISO 9001 | Hiawatha, IA | BendingWelding | ISO 9001 |
| Dahlgren Technologies LLC Welding | King George, VA | Welding | - |
| Dallas Fabrication Welding | Carrollton, TX | Welding | - |
| Dallas Machine and Tool Milling, Welding | Carrollton, TX | MillingWelding | - |
| Dallas Metal Fabricators Inc. Laser, Welding | Dallas, TX | LaserWelding | - |
| Dallas Precision Machining Milling, Turning, Bending, Laser, Welding, Waterjet, Metal AM · ISO 9001, AS9100, ITAR | Carrollton, TX | MillingTurningBendingLaserWeldingWaterjetMetal AM | ISO 9001, AS9100, ITAR |
| Damco, Inc Milling, Turning, Waterjet, Welding | New Bern, NC | MillingTurningWaterjetWelding | - |
| Danco Precision, Inc Milling, Turning, Laser, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Phoenixville, PA | MillingTurningLaserWeldingStampingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Dark Threat Fabrication LLC Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001 | Heber Springs, AR | MillingTurningLaserBendingWeldingFinishing | ISO 9001 |
| Data Electronic Services Finishing · ISO 9001, ITAR | Santa Ana, CA | Finishing | ISO 9001, ITAR |
| David Packard Company, Inc Milling, Turning, Swiss, Grinding, Finishing, Assembly · ISO 9001, ITAR | Oxford, MA | MillingTurningSwissGrindingFinishingAssembly | ISO 9001, ITAR |
| Davis Industries Milling, Turning, Punching, Bending, Welding, Assembly · ISO 9001, AS9100 | Phoenix, AZ | MillingTurningPunchingBendingWeldingAssembly | ISO 9001, AS9100 |
| Davis Tool & Die, Inc Milling, Turning, Welding, Stamping, EDM, Grinding | Abbeville, MS | MillingTurningWeldingStampingEDMGrinding | - |
| Davis Tool Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP | Hillsboro, OR | MillingTurningLaserWaterjetPunchingBendingWeldingEDMGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP |
| Davlan Engineering Inc Milling, Turning, Laser, Welding, Stamping | Saint Louis, MO | MillingTurningLaserWeldingStamping | - |
| DCP Tool Manufacturing, LLC Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Dayton, OH | MillingTurningLaserWeldingEDMGrindingFinishing | - |
| Dearborn Bortec LLC Milling, Turning, Waterjet, Welding, EDM, Grinding, Finishing · ISO 9001, AS9100, ITAR | Fryeburg, ME | MillingTurningWaterjetWeldingEDMGrindingFinishing | ISO 9001, AS9100, ITAR |
| Dechert Dynamics Corp Milling, Turning, Welding, Grinding · ISO 9001 | Palmyra, PA | MillingTurningWeldingGrinding | ISO 9001 |
| Decimal Engineering Milling, Turning, Laser, Stamping, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP | Coral Springs, FL | MillingTurningLaserStampingEDMGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP |
| Decotron Welding, Metal AM | Dallas, TX | WeldingMetal AM | - |
| Defense & Aerospace Manufacturing LLC Welding, Grinding, Finishing, Assembly | Rancho Cordova, CA | WeldingGrindingFinishingAssembly | - |
| Deines-Nitz Solutions, LLC Milling, Finishing | Erie, IL | MillingFinishing | - |
| Deking Precision Inc Turning, Swiss · ISO 9001, AS9100 | Chatsworth, CA | TurningSwiss | ISO 9001, AS9100 |
| Delco LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100 | Akron, OH | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100 |