| Ameritec Machining, Inc Milling, Turning · ISO 9001 | New Hampton, IA | MillingTurning | ISO 9001 |
| Amex Plating Inc Finishing | Santa Clara, CA | Finishing | - |
| Amherst Stainless Fabrication, LLC Turning, Welding, Waterjet | Buffalo, NY | TurningWeldingWaterjet | - |
| AMS Accurate Metal Milling, Bending, Laser, Welding, Stamping · AS9100 | Richland Hills, TX | MillingBendingLaserWeldingStamping | AS9100 |
| AMS Manufacturing Welding, EDM, Finishing, Assembly | San Jose, CA | WeldingEDMFinishingAssembly | - |
| Amscot Structural Products Corporation Turning, Welding | Dover, NJ | TurningWelding | - |
| Anaheim Precision Milling, Turning, Bending, Laser, Welding, Waterjet · ISO 9001, AS9100, NADCAP | Orange, CA | MillingTurningBendingLaserWeldingWaterjet | ISO 9001, AS9100, NADCAP |
| Anchor Fabricators Inc Laser, Punching, Bending, Welding, Stamping, Assembly | Clayton, OH | LaserPunchingBendingWeldingStampingAssembly | - |
| Ancon Gear & Instrument Corp Milling, Turning · ISO 9001, AS9100 | Amityville, NY | MillingTurning | ISO 9001, AS9100 |
| Anderson Metal Industries Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR | Franklin, PA | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR |
| Ankeny Automation, LLC Milling, Laser, Welding, Grinding, Finishing | Omaha, NE | MillingLaserWeldingGrindingFinishing | - |
| Anthony Machine Milling, Turning, Welding | San Antonio, TX | MillingTurningWelding | - |
| Aotco Holdings, LLC Finishing · ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 | Billerica, MA | Finishing | ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 |
| Ap Precision Machine Inc Milling, Turning, Waterjet, Finishing | Holliston, MA | MillingTurningWaterjetFinishing | - |
| Apex Engineered Products Milling, Turning, Waterjet, Welding, Finishing | Clark, PA | MillingTurningWaterjetWeldingFinishing | - |
| Apogee CNC Inc Milling, Welding, Grinding, Finishing · ITAR | Dexter, MI | MillingWeldingGrindingFinishing | ITAR |
| Apple Steel Rule Die Co Inc Laser | Milwaukee, WI | Laser | - |
| Arc Machine Co Inc Milling, Turning, Welding, Grinding · ISO 9001 | Henderson, KY | MillingTurningWeldingGrinding | ISO 9001 |
| Arcturus Aerospace Milling, Turning · AS9100, ITAR, NADCAP, ISO 9001 | Little Rock, AR | MillingTurning | AS9100, ITAR, NADCAP, ISO 9001 |
| Argent Fabrication LLC Bending, Welding | Seattle, WA | BendingWelding | - |
| Aristo Industries Laser, Welding · ISO 9001 | Fraser, MI | LaserWelding | ISO 9001 |
| Armec Corp Welding · ISO 9001 | Oak Ridge, TN | Welding | ISO 9001 |
| Armor Contract Manufacturing Inc Welding, Stamping, Finishing | Elkhart, IN | WeldingStampingFinishing | - |
| Armstrong Mold Corp Stamping, Casting, Assembly · ISO 9001, ITAR | East Syracuse, NY | StampingCastingAssembly | ISO 9001, ITAR |
| Arnprior Aerospace Portland, Inc Milling · ITAR, NADCAP | Portland, OR | Milling | ITAR, NADCAP |
| Arrowtech Machine Works Milling, Turning, Grinding | Eugene, OR | MillingTurningGrinding | - |
| Artifact Fabrication LLC Bending, Laser, Welding · ISO 9001, ITAR, CMMC | Rochester, NY | BendingLaserWelding | ISO 9001, ITAR, CMMC |
| ASC Machine Tools Inc Bending | Spokane Valley, WA | Bending | - |
| Asc Machining Milling | Mequon, WI | Milling | - |
| Ascend Engineering LLC Milling, Turning, Welding, Grinding, Assembly · ISO 9001 | Largo, FL | MillingTurningWeldingGrindingAssembly | ISO 9001 |
| Ascentec Engineering LLC Milling, Turning, Waterjet, EDM, Grinding | Tualatin, OR | MillingTurningWaterjetEDMGrinding | - |
| Ash-Tec Laser, Welding, Finishing | Hegins, PA | LaserWeldingFinishing | - |
| Astoria Wire Products Inc Milling, Laser, Punching, Bending, Welding | Bedford Park, IL | MillingLaserPunchingBendingWelding | - |
| Athena Manufacturing LP Milling, Assembly · ITAR | Austin, TX | MillingAssembly | ITAR |
| Atlantic Fabricating Milling, Turning, Punching, Bending, Welding, Assembly · ISO 9001 | East Granby, CT | MillingTurningPunchingBendingWeldingAssembly | ISO 9001 |
| Atlantic Metal Products, Inc Waterjet, Bending, Welding | Topping, VA | WaterjetBendingWelding | - |
| Atlas Foundry Company Inc Casting, Grinding | Marion, IN | CastingGrinding | - |
| Atlas Machine & Supply, Inc. Milling, Turning, Welding, EDM · ISO 9001 | Louisville, KY | MillingTurningWeldingEDM | ISO 9001 |
| Atlas Machine Co. Inc Milling, Turning, Welding · ISO 9001, AS9100 | Baltimore, MD | MillingTurningWelding | ISO 9001, AS9100 |
| Atlas Tool & Die Works Inc Turning, Laser, Waterjet, Welding, Stamping, EDM, Assembly | Lyons, IL | TurningLaserWaterjetWeldingStampingEDMAssembly | - |
| Atmosphere Machining LLC Milling, Turning, Waterjet, Welding, Finishing · ITAR | Tehachapi, CA | MillingTurningWaterjetWeldingFinishing | ITAR |
| Atomic Fabrications LLC. Welding | Seattle, WA | Welding | - |
| Atscott Mfg, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping, Grinding, Finishing, Assembly · ISO 9001, ITAR | Pine City, MN | MillingTurningLaserWaterjetPunchingBendingWeldingStampingGrindingFinishingAssembly | ISO 9001, ITAR |
| Aurele M Gatti Inc Milling, Turning, Waterjet | Fairless Hills, PA | MillingTurningWaterjet | - |
| Austin Machine Co Milling, Turning, Waterjet · ISO 9001 | O Fallon, MO | MillingTurningWaterjet | ISO 9001 |
| Automated Machine & Technology Inc Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Assembly · ISO 9001, ITAR | Yorktown, VA | MillingTurningWaterjetBendingWeldingEDMGrindingAssembly | ISO 9001, ITAR |
| Autopilot Inc Milling, Turning, Finishing | Bozeman, MT | MillingTurningFinishing | - |
| Avalon Mfg, Inc Milling · AS9100 | Compton, CA | Milling | AS9100 |
| Avvid Corporation Milling, Turning, Swiss, Grinding · ISO 13485 | Laramie, WY | MillingTurningSwissGrinding | ISO 13485 |
| Awerkamp Machine Co Welding | Quincy, IL | Welding | - |