| Jones Metal, Inc Milling, Laser, Waterjet, Bending, Welding, Finishing, Assembly | Mankato, MN | MillingLaserWaterjetBendingWeldingFinishingAssembly | - |
| Jonesboro Tool & Die Co Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding · AS9100, ITAR, CMMC | Jonesboro, AR | MillingTurningLaserWaterjetBendingWeldingStampingEDMGrinding | AS9100, ITAR, CMMC |
| JP Metal Fabrication, Inc. Milling, Bending, Laser, Welding | Santa Clara, CA | MillingBendingLaserWelding | - |
| Justified Performance LLC Laser, Bending, Welding, Finishing, Assembly · ISO 9001 | Rocklin, CA | LaserBendingWeldingFinishingAssembly | ISO 9001 |
| Kammerer Dynamics Inc Laser, Bending, Welding, Casting, Finishing, Assembly | Kendallville, IN | LaserBendingWeldingCastingFinishingAssembly | - |
| Kihm Metal Technologies Laser, Welding | Brazil, IN | LaserWelding | - |
| Kinross Fab & Machine Inc Milling, Turning, Laser, Welding, Grinding, Finishing | Kincheloe, MI | MillingTurningLaserWeldingGrindingFinishing | - |
| Kinship Precision LLC Milling, Turning, Swiss, Laser · ISO 9001, ISO 13485 | Melbourne, FL | MillingTurningSwissLaser | ISO 9001, ISO 13485 |
| Ko Laser Milling, Turning, Laser, Bending, Welding | Tulsa, OK | MillingTurningLaserBendingWelding | - |
| KV Engineering LLC Milling, Turning, Laser, Waterjet, Welding | Miami, FL | MillingTurningLaserWaterjetWelding | - |
| L. E. F., Inc Milling, Laser, Bending, Welding, Stamping, Finishing | Tulsa, OK | MillingLaserBendingWeldingStampingFinishing | - |
| Lacross Enterprises Inc Turning, Laser, Punching, Bending, Welding | Louisville, KY | TurningLaserPunchingBendingWelding | - |
| Laguna Tools Turning, Laser, Waterjet | Grand Prairie, TX | TurningLaserWaterjet | - |
| Lanzen Inc Milling, Laser, Welding | Bruce Twp, MI | MillingLaserWelding | - |
| Laser Metal Fabrication Laser, Bending, Welding, Assembly | Twin Falls, ID | LaserBendingWeldingAssembly | - |
| Laserbend, LLC Laser, Bending, Welding, Finishing | Tujunga, CA | LaserBendingWeldingFinishing | - |
| Laserform & Machine Inc Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Columbia, SC | TurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| Legacy Industries Laser, Welding, Stamping · ITAR | Auburn Hills, MI | LaserWeldingStamping | ITAR |
| LHM Engineering LLC Milling, Swiss, Laser, Waterjet, Stamping, EDM, Grinding, Finishing, Assembly · ISO 13485 | Manchester, MA | MillingSwissLaserWaterjetStampingEDMGrindingFinishingAssembly | ISO 13485 |
| Liberty Hill Company Milling, Turning, Swiss, Laser, Waterjet, Bending, EDM · ISO 9001, AS9100, ITAR | Huntington, WV | MillingTurningSwissLaserWaterjetBendingEDM | ISO 9001, AS9100, ITAR |
| Limestone Manufacturing LLC Milling, Turning, Laser, Bending, Welding, Metal AM, EDM, Grinding · ISO 9001, AS9100 | Somerset, KY | MillingTurningLaserBendingWeldingMetal AMEDMGrinding | ISO 9001, AS9100 |
| LJ Fabricators, Inc. Bending, Laser, Welding · ISO 9001 | Rockford, IL | BendingLaserWelding | ISO 9001 |
| LLB Metal Fabrication Limited Liability Company Turning, Laser, Waterjet, Welding | Honolulu, HI | TurningLaserWaterjetWelding | - |
| Lodolce Machine Co, Inc Milling, Turning, Laser, Welding, EDM, Assembly · ISO 9001, AS9100 | Saugerties, NY | MillingTurningLaserWeldingEDMAssembly | ISO 9001, AS9100 |
| Loftis Steel & Aluminum, Inc. Milling, Laser, Waterjet | Nashville, TN | MillingLaserWaterjet | - |
| LR Design+Build Laser, Welding, Metal AM | Columbus, OH | LaserWeldingMetal AM | - |
| Luna's Sheet Metal Inc Milling, Turning, Bending, Laser, Welding | Santa Clara, CA | MillingTurningBendingLaserWelding | - |
| LX3 Tooling Milling, Turning, Laser, Welding, Grinding · CMMC | Aledo, TX | MillingTurningLaserWeldingGrinding | CMMC |
| M B Steel Milling, Bending, Laser, Welding, Stamping | St. Louis, MO | MillingBendingLaserWeldingStamping | - |
| M&M Metals Inc. Bending, Laser, Welding | San Antonio, TX | BendingLaserWelding | - |
| Mac Smith Corp Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, Grinding | Gardena, CA | MillingTurningLaserWaterjetBendingWeldingStampingGrinding | - |
| Mac-Tech Turning, Bending, Laser, Welding | Milwaukee, WI | TurningBendingLaserWelding | - |
| Machine & Tool Manufacturing Company Milling, Laser, Waterjet, Welding, Finishing | Adel, GA | MillingLaserWaterjetWeldingFinishing | - |
| Machine Tool Engineering Milling, Turning, Swiss, Laser, Waterjet, Stamping, EDM, Grinding, Finishing · ISO 9001, AS9100, NADCAP | Charles City, IA | MillingTurningSwissLaserWaterjetStampingEDMGrindingFinishing | ISO 9001, AS9100, NADCAP |
| Machinists Inc Milling, Turning, Laser, Welding, EDM, Grinding · ISO 9001, ITAR | Seattle, WA | MillingTurningLaserWeldingEDMGrinding | ISO 9001, ITAR |
| Majestic Metals by Fathom Manufacturing Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting, Metal AM · ISO 9001, AS9100, ITAR, ISO 13485 | Denver, CO | MillingTurningBendingLaserWeldingWaterjetEDMCastingMetal AM | ISO 9001, AS9100, ITAR, ISO 13485 |
| Malone Industrial Machine, L.L.C Milling, Turning, Laser, Bending, Welding | Deer Park, TX | MillingTurningLaserBendingWelding | - |
| Manor Tool & Manufacturing Co Milling, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001, ITAR | Schiller Park, IL | MillingLaserWaterjetBendingWeldingStampingEDMGrindingFinishing | ISO 9001, ITAR |
| Manufacture.us Milling, Turning, Swiss, Laser, Finishing, Assembly | Doral, FL | MillingTurningSwissLaserFinishingAssembly | - |
| Massie Mfg Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Finishing · ITAR | Baraga, MI | MillingTurningLaserWaterjetBendingWeldingFinishing | ITAR |
| Mathias Die Co Inc Milling, Laser, Waterjet, Stamping, EDM · ISO 9001, ITAR | South Saint Paul, MN | MillingLaserWaterjetStampingEDM | ISO 9001, ITAR |
| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| Maxsteel Fabrication, LLC Milling, Turning, Laser, Welding, Finishing | Paris, TN | MillingTurningLaserWeldingFinishing | - |
| McAlpin Industries Inc. Milling, Bending, Laser, Welding, Stamping | Rochester, NY | MillingBendingLaserWeldingStamping | - |
| McKenna Metal Bending, Laser, Welding, Waterjet | Portland, OR | BendingLaserWeldingWaterjet | - |
| McKiney Manufacturing Milling, Turning, Laser, Waterjet, Bending, Welding | Mitchell, NE | MillingTurningLaserWaterjetBendingWelding | - |
| Megla Manufacturing, Inc. Milling, Bending, Laser, Welding, Waterjet | National City, CA | MillingBendingLaserWeldingWaterjet | - |
| Mercury Aircraft Inc Milling, Laser, Punching, Bending, Welding, Stamping, Assembly · ISO 9001, AS9100, ITAR | Hammondsport, NY | MillingLaserPunchingBendingWeldingStampingAssembly | ISO 9001, AS9100, ITAR |
| Meridian Manufacturing Inc Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Ballston Spa, NY | MillingTurningLaserWeldingEDMGrindingFinishing | - |