| Wildfactory Milling, Turning, Waterjet | Camarillo, CA | MillingTurningWaterjet | - |
| Wilson Precision Manufacturing LLC Milling | Dickinson, TX | Milling | - |
| Witco Inc Milling, Turning, Grinding · ISO 9001, AS9100, ITAR, NADCAP | Greenwood, MI | MillingTurningGrinding | ISO 9001, AS9100, ITAR, NADCAP |
| Wolverine Bronze Co Welding, Casting | Roseville, MI | WeldingCasting | - |
| Worldwide Instrument Parts Co Milling, Turning, EDM, Finishing · ISO 9001 | Livingston, TX | MillingTurningEDMFinishing | ISO 9001 |
| Wpa Works LLC Milling, Turning, Swiss, EDM, Finishing · ISO 9001 | Elgin, IL | MillingTurningSwissEDMFinishing | ISO 9001 |
| Xtreme Machining, Inc Milling, Turning · ISO 9001, AS9100 | Auburn, WA | MillingTurning | ISO 9001, AS9100 |
| Yakima Machine Milling, Turning, Finishing | Yakima, WA | MillingTurningFinishing | - |
| Yankee Casting Co, Inc Milling, Welding, Casting · AS9100, NADCAP | Enfield, CT | MillingWeldingCasting | AS9100, NADCAP |
| Zeco Machine Inc Milling, Turning, Welding, EDM · ISO 9001, AS9100 | Guthrie, OK | MillingTurningWeldingEDM | ISO 9001, AS9100 |
| ZI Machine Milling, Turning · ISO 9001, AS9100, ITAR | El Dorado Hills, CA | MillingTurning | ISO 9001, AS9100, ITAR |
| Zimmer Design & Manufacturing LLC Milling, Turning, Laser, Welding, EDM, Finishing · AS9100, ITAR | Leander, TX | MillingTurningLaserWeldingEDMFinishing | AS9100, ITAR |
| Zip Products Inc Milling, Turning, Swiss, Stamping, EDM, Grinding, Finishing, Assembly · ITAR | Rochester, NY | MillingTurningSwissStampingEDMGrindingFinishingAssembly | ITAR |
| Zyxaxis Inc Milling, Welding, EDM, Grinding, Assembly · AS9100, ITAR | Wichita, KS | MillingWeldingEDMGrindingAssembly | AS9100, ITAR |