| Decker Machine Works Inc Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100, ITAR | Greenfield, MA | MillingTurningSwissEDMGrinding | ISO 9001, AS9100, ITAR |
| Defelice Engineering, Inc Milling, Turning, Bending, Welding, Casting, Grinding | Mooresville, IN | MillingTurningBendingWeldingCastingGrinding | - |
| Defiant CNC Milling, Turning | Orlando, FL | MillingTurning | - |
| Deines-Nitz Solutions, LLC Milling, Finishing | Erie, IL | MillingFinishing | - |
| Deland Manufacturing Inc Milling, Turning · ISO 9001, AS9100, ITAR | Shelby Township, MI | MillingTurning | ISO 9001, AS9100, ITAR |
| Dellinger Enterprises, Ltd Milling, Turning, Laser, Bending, Welding, Stamping, Finishing | Belmont, NC | MillingTurningLaserBendingWeldingStampingFinishing | - |
| Delta Machine Company, LLC Milling, Turning, Welding, Grinding | Harbor City, CA | MillingTurningWeldingGrinding | - |
| Delta One Manufacturing LLC Milling, Turning, Laser, Welding, Finishing, Assembly | San Jose, CA | MillingTurningLaserWeldingFinishingAssembly | - |
| Deltisan Engineering LLC Milling, Turning, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Parker, CO | MillingTurningPunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Denezol Tool Co Inc Milling, Turning | Salem, OR | MillingTurning | - |
| Denver Machine Shop Milling, Turning, Welding · ISO 9001 | Henderson, CO | MillingTurningWelding | 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 | - |
| Desalvo Systems Inc Milling, Turning · ITAR | Yuma, AZ | MillingTurning | ITAR |
| Desert Engineering Group Inc Milling, Turning, Stamping, Grinding | Tucson, AZ | MillingTurningStampingGrinding | - |
| Desert West CNC LLC Milling, Turning, Finishing | El Paso, TX | MillingTurningFinishing | - |
| Design Metal, Inc Milling, Turning, Bending, Welding, Stamping · ISO 9001 | Oak Park, MI | MillingTurningBendingWeldingStamping | ISO 9001 |
| Dexter Design & Development Co Milling, Turning, EDM, Grinding, Assembly · ISO 9001 | Hillsboro, OR | MillingTurningEDMGrindingAssembly | ISO 9001 |
| DGF Industrial Innovations Group, Ltd Milling, Turning, Bending, Welding · ISO 9001 | Gilford, NH | MillingTurningBendingWelding | ISO 9001 |
| Diamond Die and Mold Milling, EDM, Grinding, Finishing · ISO 9001 | Clinton Township, MI | MillingEDMGrindingFinishing | ISO 9001 |
| Diamond Machine Works, Inc. Milling, Turning · ISO 9001, AS9100 | Seattle, WA | MillingTurning | ISO 9001, AS9100 |
| Diamond Turning Innovations, LLC Milling, Turning, Grinding | Milford, NH | MillingTurningGrinding | - |
| Diamond W Custom Machine Works LLC Milling, Turning, Laser, Waterjet, Welding, Finishing | Phillipsburg, KS | MillingTurningLaserWaterjetWeldingFinishing | - |
| Die Technology, Inc Milling, Turning, Swiss, Bending, Stamping, EDM, Grinding · ISO 9001, CMMC | Saint Michael, MN | MillingTurningSwissBendingStampingEDMGrinding | ISO 9001, CMMC |
| Die-Mension Corp Milling, Turning, Welding, Stamping, EDM, Grinding | Brunswick, OH | MillingTurningWeldingStampingEDMGrinding | - |
| Digital Machining Systems LLC Milling, Turning, Welding, Assembly · ISO 9001 | Duson, LA | MillingTurningWeldingAssembly | ISO 9001 |
| Dimark Precision Machining,, Inc Milling, Turning, Welding, Grinding | Pembroke, MA | MillingTurningWeldingGrinding | - |
| Dinucci Corp Milling, Turning · AS9100 | Concord, CA | MillingTurning | AS9100 |
| Distinctive Machining LLC Milling, Welding, Grinding, Finishing | Zeeland, MI | MillingWeldingGrindingFinishing | - |
| Diversified Machining Inc Milling, Welding | Forest Hill, MD | MillingWelding | - |
| Diversitech Inc Milling, Turning, Assembly · ISO 9001 | Riverdale, NJ | MillingTurningAssembly | ISO 9001 |
| Dixon Tool & Die Co Inc Milling, Turning, Waterjet, Welding, EDM, Grinding · ISO 9001, CMMC | Tyrone, PA | MillingTurningWaterjetWeldingEDMGrinding | ISO 9001, CMMC |
| DJW Assembly Inc Milling, Turning | Arlington Heights, IL | MillingTurning | - |
| DK Machining LLC Milling, Turning, Welding, Assembly · ISO 9001, ITAR | Molalla, OR | MillingTurningWeldingAssembly | ISO 9001, ITAR |
| Dolphin Manufacturing, Inc Milling, Turning, Finishing, Assembly · ISO 9001 | Taylor, MI | MillingTurningFinishingAssembly | ISO 9001 |
| Domaille Engineering, LLC Milling, Turning, Welding, EDM, Grinding, Assembly | Rochester, MN | MillingTurningWeldingEDMGrindingAssembly | - |
| Donahue Industries, Incorporated Milling, Turning, Swiss, Punching, Bending, Welding, Stamping, EDM, Grinding, Finishing | Shrewsbury, MA | MillingTurningSwissPunchingBendingWeldingStampingEDMGrindingFinishing | - |
| Donsco, Inc Milling, Welding, Casting | Wrightsville, PA | MillingWeldingCasting | - |
| Douglas Machine & Engineering Milling, Turning, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, CMMC | Davenport, IA | MillingTurningBendingWeldingEDM | ISO 9001, AS9100, ITAR, CMMC |
| DP Machining Inc Milling, Turning, Swiss, Stamping, Finishing | La Verne, CA | MillingTurningSwissStampingFinishing | - |
| Dpi Inc Milling, Turning | Hatboro, PA | MillingTurning | - |
| Draeving Machine Tool, Inc Milling, Turning, Welding, EDM | Beloit, WI | MillingTurningWeldingEDM | - |
| Dresco Machining & Fabrication Milling, Turning, Waterjet, Welding · ISO 9001 | Bay City, MI | MillingTurningWaterjetWelding | ISO 9001 |
| DRM Industries Corp Milling, Turning, Laser, Welding, Casting · ISO 9001 | Lake Delton, WI | MillingTurningLaserWeldingCasting | ISO 9001 |
| DRP Machine Milling, Turning, Grinding · ISO 9001 | West Valley City, UT | MillingTurningGrinding | ISO 9001 |
| DT Precision, LLC Milling, Turning, Swiss · ISO 9001, AS9100, ITAR, ISO 13485 | San Jose, CA | MillingTurningSwiss | ISO 9001, AS9100, ITAR, ISO 13485 |
| Dual Machine Milling, Turning, Welding · ISO 9001, AS9100 | Indianapolis, IN | MillingTurningWelding | ISO 9001, AS9100 |
| Dualtron Manufacturing Milling, Laser, Punching, Welding, Finishing, Assembly | West Babylon, NY | MillingLaserPunchingWeldingFinishingAssembly | - |
| Dunham Products, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001 | Walton Hills, OH | MillingTurningSwissGrindingFinishing | ISO 9001 |
| Dutchy Enterprises LLC Milling, Waterjet, Welding | Cocoa, FL | MillingWaterjetWelding | - |