| Continental Industries Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| 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 |
| Council Stainless & Sheet Metal Bending, Welding, Waterjet | Oklahoma City, OK | BendingWeldingWaterjet | - |
| Coventry Industries LLC Waterjet, Welding, EDM · ITAR | Holly, MI | WaterjetWeldingEDM | ITAR |
| 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 | - |
| Creative Machining Solutions Welding, Finishing | Walford, IA | WeldingFinishing | - |
| Creative Metal Products Inc Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Neenah, WI | PunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Criterion Manufacturing Turning, Welding | Waterloo, IA | TurningWelding | - |
| Critical Defense Inc Milling, Turning, Bending, Welding, Grinding, Assembly | Windber, PA | MillingTurningBendingWeldingGrindingAssembly | - |
| 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 | - |
| 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 Laser Works LLC Laser, Bending, Welding | Addison, IL | LaserBendingWelding | - |
| 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 Manufacturing Services, Inc Laser, Welding, Finishing, Assembly · ISO 9001 | Princeton, WV | LaserWeldingFinishingAssembly | ISO 9001 |
| 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 Fabrication LLC Welding | Tucson, AZ | Welding | - |
| Cutting Edge Machining & Automation-Qtr, LLC Milling, Turning, Swiss, Laser, Welding, EDM, Assembly | North Versailles, PA | MillingTurningSwissLaserWeldingEDMAssembly | - |
| Cutting Edge Solutions Mfg & Mro LLC Welding | Yuma, AZ | Welding | - |
| Cutting Solutions Turning, Laser, Waterjet, Bending, Welding, Grinding, Finishing, Assembly | Zeeland, MI | TurningLaserWaterjetBendingWeldingGrindingFinishingAssembly | - |
| 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 |
| 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 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 |
| 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 | - |