| American Fab Milling, Laser, Bending, Welding | Spring Lake, MI | MillingLaserBendingWelding | - |
| American Machine Tools Co. Milling, Turning, Bending | Chicago, IL | MillingTurningBending | - |
| American Machining Inc Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Ottawa, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| American Machining Solutions Inc Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100 | Willow Spring, NC | MillingTurningSwissEDMGrinding | ISO 9001, AS9100 |
| American Metal Fab Inc Milling, Laser, Punching, Bending, Welding, Stamping · ISO 9001 | Three Rivers, MI | MillingLaserPunchingBendingWeldingStamping | ISO 9001 |
| American Metalcraft, Inc Waterjet, Punching, Bending, Welding, Finishing, Assembly | Villa Rica, GA | WaterjetPunchingBendingWeldingFinishingAssembly | - |
| American Shop Tools LLC Milling, Turning | Conroe, TX | MillingTurning | - |
| American Stainless Fabricators LLC Welding | Dickson, TN | Welding | - |
| American Swiss Products Turning, Swiss · ISO 9001 | Pittsford, NY | TurningSwiss | ISO 9001 |
| American Waterjet Cutting LLC Milling, Waterjet, Finishing | Winfield, IA | MillingWaterjetFinishing | - |
| Amerimac Machining Corp Milling, Turning, Welding | Jackson, MS | MillingTurningWelding | - |
| Amex Plating Inc Finishing | Santa Clara, CA | Finishing | - |
| Amg Engineering & Machining Milling, Turning, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, IATF 16949 | Indianapolis, IN | MillingTurningBendingWeldingEDM | ISO 9001, AS9100, ITAR, IATF 16949 |
| Amincor Milling, Turning, Swiss, Laser, Punching, Bending, Welding, Stamping, EDM, Grinding, Finishing, Assembly · ISO 9001, ITAR, CMMC | Belton, MO | MillingTurningSwissLaserPunchingBendingWeldingStampingEDMGrindingFinishingAssembly | ISO 9001, ITAR, CMMC |
| AMS Manufacturing Welding, EDM, Finishing, Assembly | San Jose, CA | WeldingEDMFinishingAssembly | - |
| Amscot Structural Products Corporation Turning, Welding | Dover, NJ | TurningWelding | - |
| Anchor Fabricators Inc Laser, Punching, Bending, Welding, Stamping, Assembly | Clayton, OH | LaserPunchingBendingWeldingStampingAssembly | - |
| Anchor-Harvey Components LLC Milling, Forging, Finishing · ISO 9001, AS9100 | Freeport, IL | MillingForgingFinishing | ISO 9001, AS9100 |
| Ancon Gear & Instrument Corp Milling, Turning · ISO 9001, AS9100 | Amityville, NY | MillingTurning | ISO 9001, AS9100 |
| Anderson Express Inc Milling, Turning, Casting | Muskegon, MI | MillingTurningCasting | - |
| Anderson Metal Industries Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR | Franklin, PA | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR |
| 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 | - |
| Antonio's Metal Works, Inc Welding | El Cajon, CA | Welding | - |
| Antron Engineering & Machine Co Inc Milling, Turning, Swiss, Welding, EDM, Assembly | Bellingham, MA | MillingTurningSwissWeldingEDMAssembly | - |
| Anvil Iron Works Welding | Philadelphia, PA | Welding | - |
| Ap Precision Metals, Inc Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly · ISO 9001 | San Diego, CA | LaserPunchingBendingWeldingStampingFinishingAssembly | ISO 9001 |
| Apex Metal Fabricating & Mach Bending, Laser, Welding | Toledo, OH | BendingLaserWelding | - |
| 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 |
| Apparatus Mfg., Inc Welding, Grinding, Finishing, Assembly | Poughkeepsie, NY | WeldingGrindingFinishingAssembly | - |
| Arc Machine Co Inc Milling, Turning, Welding, Grinding · ISO 9001 | Henderson, KY | MillingTurningWeldingGrinding | ISO 9001 |
| Arcadian Systems LLC Finishing | Livingston, NJ | Finishing | - |
| Arcal Precision Components Inc Milling, Turning, Welding · ISO 9001, AS9100 | Tucson, AZ | MillingTurningWelding | ISO 9001, AS9100 |
| Arek Solutions LLC Welding · ISO 9001 | Stafford, TX | Welding | ISO 9001 |
| Argent Fabrication LLC Bending, Welding | Seattle, WA | BendingWelding | - |
| Aria Dynamics LLC Milling, Turning · ITAR | Far Hills, NJ | MillingTurning | ITAR |
| Ariam Industries LLC Milling, Turning, Welding | Baraga, MI | MillingTurningWelding | - |
| Aristo Industries Laser, Welding · ISO 9001 | Fraser, MI | LaserWelding | ISO 9001 |
| Arizona CNC Equipment Milling, Turning, Bending, EDM | Tempe, AZ | MillingTurningBendingEDM | - |
| Arizona Metal Craft Bending, Welding | Tucson, AZ | BendingWelding | - |
| Armes Precision Milling, Turning, Laser, Bending, Welding, Assembly · ISO 9001, ITAR | Lynchburg, VA | MillingTurningLaserBendingWeldingAssembly | ISO 9001, ITAR |
| 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 |
| Arrowtech Machine Works Milling, Turning, Grinding | Eugene, OR | MillingTurningGrinding | - |