| Anderson Precision Machining Milling, Casting, Metal AM · AS9100, ITAR | Tucson, AZ | MillingCastingMetal AM | AS9100, ITAR |
| Angeles Precision Engineering LLC Milling, Turning, Assembly · ISO 9001, ITAR | Ontario, CA | MillingTurningAssembly | ISO 9001, ITAR |
| Angelino Precision Engineering LLC Milling | Kissimmee, FL | Milling | - |
| Ankeny Automation, LLC Milling, Laser, Welding, Grinding, Finishing | Omaha, NE | MillingLaserWeldingGrindingFinishing | - |
| Ansco Machine Co Milling, Turning, Punching, Grinding, Finishing · ISO 9001, ITAR | Peninsula, OH | MillingTurningPunchingGrindingFinishing | ISO 9001, ITAR |
| Anthony Machine Milling, Turning, Welding | San Antonio, TX | MillingTurningWelding | - |
| Antron Engineering & Machine Co Inc Milling, Turning, Swiss, Welding, EDM, Assembly | Bellingham, MA | MillingTurningSwissWeldingEDMAssembly | - |
| Apex Precision CNC Milling, Turning, Punching, Bending, Stamping, Casting, EDM, Grinding, Assembly · ITAR, CMMC | Orem, UT | MillingTurningPunchingBendingStampingCastingEDMGrindingAssembly | ITAR, CMMC |
| Apm Machine LLC Milling, Turning | Plainville, CT | MillingTurning | - |
| Apogee CNC Inc Milling, Welding, Grinding, Finishing · ITAR | Dexter, MI | MillingWeldingGrindingFinishing | ITAR |
| Arc Machine Co Inc Milling, Turning, Welding, Grinding · ISO 9001 | Henderson, KY | MillingTurningWeldingGrinding | ISO 9001 |
| Arcal Precision Components Inc Milling, Turning, Welding · ISO 9001, AS9100 | Tucson, AZ | MillingTurningWelding | ISO 9001, AS9100 |
| Aria Dynamics LLC Milling, Turning · ITAR | Far Hills, NJ | MillingTurning | ITAR |
| Ariam Industries LLC Milling, Turning, Welding | Baraga, MI | MillingTurningWelding | - |
| Arizona CNC Equipment Milling, Turning, Bending, EDM | Tempe, AZ | MillingTurningBendingEDM | - |
| Armes Precision Milling, Turning, Laser, Bending, Welding, Assembly · ISO 9001, ITAR | Lynchburg, VA | MillingTurningLaserBendingWeldingAssembly | ISO 9001, ITAR |
| Arrowtech Machine Works Milling, Turning, Grinding | Eugene, OR | MillingTurningGrinding | - |
| Art CNC Machining LLC Milling, Turning, Assembly · ISO 9001 | Bridgeview, IL | MillingTurningAssembly | ISO 9001 |
| Artisan Machining, Inc Milling, Finishing | Ronkonkoma, NY | MillingFinishing | - |
| Asc Machining Milling | Mequon, WI | Milling | - |
| Ascend Engineering LLC Milling, Turning, Welding, Grinding, Assembly · ISO 9001 | Largo, FL | MillingTurningWeldingGrindingAssembly | ISO 9001 |
| Ascend Mfg Corp Milling, Laser, Welding, Stamping, Finishing | Anaheim, CA | MillingLaserWeldingStampingFinishing | - |
| Ascentec Engineering LLC Milling, Turning, Waterjet, EDM, Grinding | Tualatin, OR | MillingTurningWaterjetEDMGrinding | - |
| Ashore Manufacturing Group LLC Milling, Turning, Stamping, EDM, Grinding · ISO 9001, AS9100, ITAR, CMMC | Berlin Center, OH | MillingTurningStampingEDMGrinding | ISO 9001, AS9100, ITAR, CMMC |
| Ast Manufacturing Milling, Laser, Punching, Bending, Welding, Assembly · ISO 9001 | Grand Prairie, TX | MillingLaserPunchingBendingWeldingAssembly | ISO 9001 |
| Astley Precision Machine Co Milling, Turning · ISO 9001, ITAR | Irwin, PA | MillingTurning | ISO 9001, ITAR |
| Astro Machine & Tool Work Milling, Turning, Finishing | Tyler, TX | MillingTurningFinishing | - |
| Astro Machine Works Milling, Turning, Welding, Assembly · ISO 9001, CMMC | Ephrata, PA | MillingTurningWeldingAssembly | ISO 9001, CMMC |
| 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 |
| Atlas Machine & Supply, Inc. Milling, Turning, Welding, EDM · ISO 9001 | Louisville, KY | MillingTurningWeldingEDM | ISO 9001 |
| Atmosphere Machining LLC Milling, Turning, Waterjet, Welding, Finishing · ITAR | Tehachapi, CA | MillingTurningWaterjetWeldingFinishing | ITAR |
| Aurora Advanced Manufacturing LLC Milling, Turning | Rocky Hill, CT | MillingTurning | - |
| Austin Dynamics, Inc. Milling, Turning · ISO 9001, AS9100, ITAR | Cedar Park, TX | MillingTurning | ISO 9001, AS9100, ITAR |
| Austin Machine Co Milling, Turning, Waterjet · ISO 9001 | O Fallon, MO | MillingTurningWaterjet | ISO 9001 |
| Auto-Turn Acquisition, LLC Milling, Turning, Welding, Stamping, Grinding, Finishing · ISO 9001, AS9100 | Tulsa, OK | MillingTurningWeldingStampingGrindingFinishing | ISO 9001, AS9100 |
| 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 |
| Avans Machine, Inc Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100, ISO 13485 | Scottsboro, AL | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100, ISO 13485 |
| Avanti Engineering Inc Milling, Turning, Swiss, EDM, Grinding, Finishing, Assembly · ISO 9001 | Glendale Heights, IL | MillingTurningSwissEDMGrindingFinishingAssembly | ISO 9001 |
| Axion Labs Inc Milling, Turning, Finishing · ISO 9001, AS9100, ITAR, ISO 13485 | Westlake, OH | MillingTurningFinishing | ISO 9001, AS9100, ITAR, ISO 13485 |
| Axis CNC Inc Milling | Ware, MA | Milling | - |
| Axis Product Development, Inc Milling · ITAR | Santa Ana, CA | Milling | ITAR |
| Axton Robotics LLC Milling, Turning, Finishing | San Diego, CA | MillingTurningFinishing | - |
| B & A Co Inc Milling, Turning · ISO 9001, AS9100 | Milford, CT | MillingTurning | ISO 9001, AS9100 |
| B & B Machine EST. 1948 Milling, Turning, Welding · ISO 9001, ITAR | Denver, CO | MillingTurningWelding | ISO 9001, ITAR |
| B & D Precision Welding Milling, Turning, Welding, Grinding | Pomona, CA | MillingTurningWeldingGrinding | - |
| B & F Modern Manufacturing, Inc Milling, Turning, Assembly | Santa Ana, CA | MillingTurningAssembly | - |
| B & J Specialty Inc Milling, Welding, EDM | Wawaka, IN | MillingWeldingEDM | - |