| Commercial Tool & Die Inc Milling, Turning, Welding, Grinding | Marshall, VA | MillingTurningWeldingGrinding | - |
| Compucraft Fabricators Inc Milling, Turning, Laser, Punching, Bending, Welding, Grinding, Finishing · ISO 9001, ITAR | Montgomeryville, PA | MillingTurningLaserPunchingBendingWeldingGrindingFinishing | ISO 9001, ITAR |
| Computer Components Corporation Milling, Turning, Punching, Bending, Welding, Assembly · ISO 9001, ITAR | Philadelphia, PA | MillingTurningPunchingBendingWeldingAssembly | ISO 9001, ITAR |
| 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 | - |
| 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 | - |
| Contract Machining Milling, Turning, Welding · ISO 9001 | Lexington, KY | MillingTurningWelding | ISO 9001 |
| Copen Machine, Inc Milling, Turning, Swiss, Welding, Grinding · ISO 9001 | Kent, OH | MillingTurningSwissWeldingGrinding | ISO 9001 |
| 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 Defense Inc Milling, Turning, Bending, Welding, Grinding, Assembly | Windber, PA | MillingTurningBendingWeldingGrindingAssembly | - |
| 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 |
| 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 & 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 Metal Fabricators Milling, Bending, Laser, Welding | Richmond, VA | MillingBendingLaserWelding | - |
| Custom Metal Works Milling, Bending, Welding | Tulsa, OK | MillingBendingWelding | - |
| Custom Metalcraft Milling, Bending, Welding | Springfield, MO | MillingBendingWelding | - |
| Cutco Metal Sawing LLC Milling, Turning, Welding, Grinding | Burleson, TX | MillingTurningWeldingGrinding | - |
| Cutting Edge Fabrication Inc Milling, Bending, Laser, Welding · ISO 9001 | Milwaukee, WI | MillingBendingLaserWelding | ISO 9001 |
| Cutting Edge Machining & Automation-Qtr, LLC Milling, Turning, Swiss, Laser, Welding, EDM, Assembly | North Versailles, PA | MillingTurningSwissLaserWeldingEDMAssembly | - |
| 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. 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 |
| Dallas Precision Machining Milling, Turning, Bending, Laser, Welding, Waterjet, Metal AM · ISO 9001, AS9100, ITAR | Carrollton, TX | MillingTurningBendingLaserWeldingWaterjetMetal AM | ISO 9001, AS9100, ITAR |
| Danco Precision, Inc Milling, Turning, Laser, Welding, Stamping, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Phoenixville, PA | MillingTurningLaserWeldingStampingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Danser, Inc Milling, Laser, Punching, Bending, Welding | Davisville, WV | MillingLaserPunchingBendingWelding | - |
| Dark Threat Fabrication LLC Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001 | Heber Springs, AR | MillingTurningLaserBendingWeldingFinishing | ISO 9001 |
| Davis Tool & Die, Inc Milling, Turning, Welding, Stamping, EDM, Grinding | Abbeville, MS | MillingTurningWeldingStampingEDMGrinding | - |
| Dechert Dynamics Corp Milling, Turning, Welding, Grinding · ISO 9001 | Palmyra, PA | MillingTurningWeldingGrinding | ISO 9001 |
| Deperini Metal Fabricators Milling, Laser, Punching, Bending, Welding, Grinding, Finishing · ISO 9001 | Gaithersburg, MD | MillingLaserPunchingBendingWeldingGrindingFinishing | ISO 9001 |
| Derecktor Marine Technology LLC Milling, Turning, Waterjet, Welding | Bristol, RI | MillingTurningWaterjetWelding | - |
| Design Metal, Inc Milling, Turning, Bending, Welding, Stamping · ISO 9001 | Oak Park, MI | MillingTurningBendingWeldingStamping | ISO 9001 |
| Dessureau Machines Inc Milling, Turning, Welding | Berlin, VT | MillingTurningWelding | - |
| Deval Life Cycle Support LLC Milling, Turning, Welding, Assembly · ISO 9001, AS9100 | Philadelphia, PA | MillingTurningWeldingAssembly | ISO 9001, AS9100 |
| DGF Industrial Innovations Group, Ltd Milling, Turning, Bending, Welding · ISO 9001 | Gilford, NH | MillingTurningBendingWelding | ISO 9001 |
| Diamond W Custom Machine Works LLC Milling, Turning, Laser, Waterjet, Welding, Finishing | Phillipsburg, KS | MillingTurningLaserWaterjetWeldingFinishing | - |
| Die Craft Milling, Turning, Welding, Waterjet · ISO 9001 | Cincinnati, OH | MillingTurningWeldingWaterjet | ISO 9001 |