| Numericraft, Inc Milling, Turning, Finishing, Assembly | Tucson, AZ | MillingTurningFinishingAssembly | - |
| NW4S Inc Milling, Punching, Bending, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Lewiston, ID | MillingPunchingBendingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| O & F Machine Products Co Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100, ITAR, NADCAP | Joplin, MO | MillingTurningSwissEDMGrinding | ISO 9001, AS9100, ITAR, NADCAP |
| O. W. Landergren, Inc Milling, Laser, Punching, Bending, Welding, Stamping, EDM, Grinding, Finishing | Pittsfield, MA | MillingLaserPunchingBendingWeldingStampingEDMGrindingFinishing | - |
| Oak Ridge Tool-Engineering Inc Milling, Turning, Welding, EDM, Grinding | Oak Ridge, TN | MillingTurningWeldingEDMGrinding | - |
| Ohio Metal Fabricating Inc Turning, Bending, Laser, Welding, Stamping · AS9100 | Dayton, OH | TurningBendingLaserWeldingStamping | AS9100 |
| Olympus Foundry Welding, Casting · AS9100, NADCAP | Millcreek, UT | WeldingCasting | AS9100, NADCAP |
| Omni Machine Works Inc Milling, Turning, Welding, EDM, Grinding | Covington, GA | MillingTurningWeldingEDMGrinding | - |
| OMS Precision Machining Milling, Turning, Swiss, Casting, Grinding, Finishing · ISO 9001, ITAR | Oshkosh, WI | MillingTurningSwissCastingGrindingFinishing | ISO 9001, ITAR |
| Pacific Precision Machine Inc Milling, Turning, Welding | Sonora, CA | MillingTurningWelding | - |
| Paligen Technologies Welding, Forging | Garland, TX | WeldingForging | - |
| Panther Precision Machine Inc Milling, Turning, Welding | Anoka, MN | MillingTurningWelding | - |
| Phoenix Manufacturing, Inc Milling, Turning, Waterjet, EDM · ISO 9001, AS9100, NADCAP | Enfield, CT | MillingTurningWaterjetEDM | ISO 9001, AS9100, NADCAP |
| Planet Products Corporation Milling, Turning, Grinding | Cincinnati, OH | MillingTurningGrinding | - |
| Pme of Ohio, Inc Welding, Casting, Grinding | Minden, NV | WeldingCastingGrinding | - |
| Pol-Tech Machining, LLC Milling, Turning, Laser, Punching, Bending, Welding, EDM, Finishing · ISO 9001 | Woodruff, SC | MillingTurningLaserPunchingBendingWeldingEDMFinishing | ISO 9001 |
| Polaris Engineering Inc Milling, Turning, Welding, EDM, Grinding | Fraser, MI | MillingTurningWeldingEDMGrinding | - |
| Port City Metal Services Milling, Welding | Tulsa, OK | MillingWelding | - |
| Precision Defense Services Inc Milling, Turning, Waterjet, Welding, EDM, Grinding, Finishing · ISO 9001, AS9100 | Irwin, PA | MillingTurningWaterjetWeldingEDMGrindingFinishing | ISO 9001, AS9100 |
| Precision Die Systems Corp Milling, Welding, Grinding | Chippewa Falls, WI | MillingWeldingGrinding | - |
| Precision Equipment Inc Milling, Turning, Grinding, Finishing | Portland, OR | MillingTurningGrindingFinishing | - |
| Profab Solutions, LLC Welding | Bellefontaine, OH | Welding | - |
| R & S Machining Inc Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100 | Saint Louis, MO | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100 |
| R. A. Zweig, Inc Milling, Swiss, Finishing, Assembly | Glenview, IL | MillingSwissFinishingAssembly | - |
| R. B. Machine Company, Inc Turning, Welding, Grinding · ISO 9001, AS9100 | Phoenix, AZ | TurningWeldingGrinding | ISO 9001, AS9100 |
| Rah Industries Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100, NADCAP | Santa Clarita, CA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100, NADCAP |
| Rathburn Precision Machining Milling, Turning, Swiss, EDM | Auburn, IN | MillingTurningSwissEDM | - |
| Ravelin Inc Milling, Metal AM · ITAR | Cincinnati, OH | MillingMetal AM | ITAR |
| RBH Aerospace Inc Milling, Turning, Waterjet, Bending | Lakewood, CA | MillingTurningWaterjetBending | - |
| RCI Custom Milling, Laser, Bending, Welding, Finishing · ISO 9001 | Frederick, MD | MillingLaserBendingWeldingFinishing | ISO 9001 |
| Reader Precision Solutions, Inc Milling, Turning, Swiss | Elkhorn, WI | MillingTurningSwiss | - |
| Resivine LLC Milling, Turning, Waterjet, EDM, Grinding | Houston, TX | MillingTurningWaterjetEDMGrinding | - |
| Reuss Industries, Inc Milling, Turning, Waterjet, Welding, EDM, Grinding | Madison, PA | MillingTurningWaterjetWeldingEDMGrinding | - |
| Revolution Precision Machining LLC Swiss, Grinding, Finishing · ISO 9001, AS9100 | Tulsa, OK | SwissGrindingFinishing | ISO 9001, AS9100 |
| RMC Engine Rebuilding Equipment, Inc Milling | Saginaw, MI | Milling | - |
| Rozak Engineering, Inc Milling, Turning · ISO 9001, AS9100, ITAR, NADCAP | Fullerton, CA | MillingTurning | ISO 9001, AS9100, ITAR, NADCAP |
| S & S Commercial Fishing Equipment, Incorporated Milling, Turning, Welding | Roseville, CA | MillingTurningWelding | - |
| Sabrin Turning, Welding, EDM, Assembly · AS9100 | Pasadena, CA | TurningWeldingEDMAssembly | AS9100 |
| Sanders Metal Products Inc Milling, Turning, Bending, Welding | Fargo, ND | MillingTurningBendingWelding | - |
| Semco Machine Corporation Milling, Turning | Plainville, MA | MillingTurning | - |
| Soflo Machining Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing · ISO 9001, AS9100 | Coral Springs, FL | MillingTurningLaserWaterjetWeldingGrindingFinishing | ISO 9001, AS9100 |
| Spring Grove Sheet Metal Bending, Laser, Welding | Cincinnati, OH | BendingLaserWelding | - |
| Stark Industrial, LLC Milling, Turning, Swiss, Welding, EDM, Grinding · ISO 9001 | North Canton, OH | MillingTurningSwissWeldingEDMGrinding | ISO 9001 |
| Stephens Precision, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Bradford, VT | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Stuecklen Manufacturing Co Bending, Finishing | Franklin Park, IL | BendingFinishing | - |
| Sulzer Machine & Manufacturing Inc Milling, Welding, Grinding · ISO 9001 | Mosinee, WI | MillingWeldingGrinding | ISO 9001 |
| Suntiger Industries LLC Welding · ISO 9001, AS9100, ITAR | Oceanside, CA | Welding | ISO 9001, AS9100, ITAR |
| Super Web Digital, Inc Milling, Turning, Welding, Grinding | West Babylon, NY | MillingTurningWeldingGrinding | - |
| Superior Machine & Tool Milling, Turning, Welding · ISO 9001 | Fort Wayne, IN | MillingTurningWelding | ISO 9001 |
| Superior Tooling Inc Milling, Turning, Swiss, Bending, Welding, Stamping, EDM, Grinding · ISO 9001 | Wapello, IA | MillingTurningSwissBendingWeldingStampingEDMGrinding | ISO 9001 |