| D&T Dynamics LLC Milling | Hyrum, UT | Milling | - |
| DAD Manufacturing, Inc. Bending, Welding · ISO 9001 | Hiawatha, IA | BendingWelding | ISO 9001 |
| Dahlgren Technologies LLC Welding | King George, VA | Welding | - |
| Dalton Manufacturing Group Inc Milling, Turning, Grinding · ISO 9001, CMMC | Amesbury, MA | MillingTurningGrinding | ISO 9001, CMMC |
| Damco, Inc Milling, Turning, Waterjet, Welding | New Bern, NC | MillingTurningWaterjetWelding | - |
| Danser, Inc Milling, Laser, Punching, Bending, Welding | Davisville, WV | MillingLaserPunchingBendingWelding | - |
| Davis Machine Works of Opelika Inc Welding | Opelika, AL | Welding | - |
| Dawid Manufacturing Inc Milling, Welding | Ansonia, CT | MillingWelding | - |
| Decimal Engineering Milling, Turning, Laser, Stamping, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP | Coral Springs, FL | MillingTurningLaserStampingEDMGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP |
| Decker Machine Works Inc Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100, ITAR | Greenfield, MA | MillingTurningSwissEDMGrinding | ISO 9001, AS9100, ITAR |
| Decotron Welding, Metal AM | Dallas, TX | WeldingMetal AM | - |
| Defense & Aerospace Manufacturing LLC Welding, Grinding, Finishing, Assembly | Rancho Cordova, CA | WeldingGrindingFinishingAssembly | - |
| 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 | - |
| Des Moines Metal Fab Bending, Laser, Welding | Des Moines, IA | BendingLaserWelding | - |
| Desert Metal Works Bending, Laser, Welding, Waterjet | Tucson, AZ | BendingLaserWeldingWaterjet | - |
| Desert Precision Manufacturing Bending, Laser, Welding · ISO 9001 | Tucson, AZ | BendingLaserWelding | ISO 9001 |
| Designed With Sparks LLC Welding | Usk, WA | Welding | - |
| Dessureau Machines Inc Milling, Turning, Welding | Berlin, VT | MillingTurningWelding | - |
| Deweys Service Company, LLC Laser, Welding, Grinding | Columbia, SC | LaserWeldingGrinding | - |
| Dicostanzo Welding Services LLC Welding | Anderson, SC | Welding | - |
| Die Craft Milling, Turning, Welding, Waterjet · ISO 9001 | Cincinnati, OH | MillingTurningWeldingWaterjet | ISO 9001 |
| Die-Cut Products Co Bending, Laser, Welding, Waterjet, EDM, Stamping | Cleveland, OH | BendingLaserWeldingWaterjetEDMStamping | - |
| Distinctive Machining LLC Milling, Welding, Grinding, Finishing | Zeeland, MI | MillingWeldingGrindingFinishing | - |
| Dms-South/bailey Tool LLC Milling, Turning, Welding, Stamping, EDM | Lancaster, TX | MillingTurningWeldingStampingEDM | - |
| Dominguez Sheet Metal Works, Inc Welding | El Paso, TX | Welding | - |
| Donal Machine Inc Laser, Welding, Finishing · NADCAP | Petaluma, CA | LaserWeldingFinishing | NADCAP |
| Donsco, Inc Milling, Welding, Casting | Wrightsville, PA | MillingWeldingCasting | - |
| Draeving Machine Tool, Inc Milling, Turning, Welding, EDM | Beloit, WI | MillingTurningWeldingEDM | - |
| DRM Industries Corp Milling, Turning, Laser, Welding, Casting · ISO 9001 | Lake Delton, WI | MillingTurningLaserWeldingCasting | ISO 9001 |
| Dutchy Enterprises LLC Milling, Waterjet, Welding | Cocoa, FL | MillingWaterjetWelding | - |
| Dynamic Marine Machining Welding | Spring Valley, CA | Welding | - |
| Dynamic Metal Innovations LLC Laser, Bending, Welding, Finishing, Assembly · ITAR | Emmaus, PA | LaserBendingWeldingFinishingAssembly | ITAR |
| E.H. Schwab Milling, Turning, Laser, Punching, Bending, Welding · ISO 9001 | Turtle Creek, PA | MillingTurningLaserPunchingBendingWelding | ISO 9001 |
| Eagle Magnetic Co Inc Laser, Welding, Finishing · ISO 9001 | Indianapolis, IN | LaserWeldingFinishing | ISO 9001 |
| Eagle Valley Industries, LLC Turning, Waterjet, Bending, Welding | Penn Valley, CA | TurningWaterjetBendingWelding | - |
| Echelbarger Precision Machining Milling, Swiss, Waterjet, Bending, Welding, EDM, Finishing · ISO 9001 | Kokomo, IN | MillingSwissWaterjetBendingWeldingEDMFinishing | ISO 9001 |
| Edker Industries LLC Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly | Bala Cynwyd, PA | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | - |
| El Ironworks LLC Bending, Welding, Finishing · ISO 9001 | Toney, AL | BendingWeldingFinishing | ISO 9001 |
| Electro Erosion Specialties, Inc Milling, Turning, Laser, Welding, EDM, Grinding | Renton, WA | MillingTurningLaserWeldingEDMGrinding | - |
| Electronic Carbide, Inc Milling, Turning, EDM, Grinding · ITAR | Grass Valley, CA | MillingTurningEDMGrinding | ITAR |
| Electronic Sheet Metal Craftsm Milling, Turning, Laser, Punching, Bending, Welding, Grinding, Assembly | Stoughton, MA | MillingTurningLaserPunchingBendingWeldingGrindingAssembly | - |
| Elemental Design & Machinery, LLC Milling | Chattanooga, TN | Milling | - |
| eMachineShop Milling, Turning, Bending, Laser, Welding, Waterjet, Stamping, Metal AM · ITAR | Mahwah, NJ | MillingTurningBendingLaserWeldingWaterjetStampingMetal AM | ITAR |
| Empire Metal Products Turning, Bending, Welding | Phoenix, AZ | TurningBendingWelding | - |
| En.Zo Metal Milling, Bending, Laser, Welding, Waterjet | Brooklyn, NY | MillingBendingLaserWeldingWaterjet | - |
| Engineered Mechanical Systems Inc Milling, Turning, Laser, Bending, Welding | Chattanooga, TN | MillingTurningLaserBendingWelding | - |
| Engineered Tooling Systems, Inc Milling, Laser, Welding, Stamping, Casting, Grinding | Grand Rapids, MI | MillingLaserWeldingStampingCastingGrinding | - |
| Engineering & Sheetmetal Specialist, LLC Welding, Finishing | La Vergne, TN | WeldingFinishing | - |