| JDM Machining Inc Milling, Turning, Swiss, Bending, Welding, EDM, Grinding · ISO 9001, AS9100 | Staples, MN | MillingTurningSwissBendingWeldingEDMGrinding | ISO 9001, AS9100 |
| Jkeys LLC Laser, Bending, Finishing | Willis, TX | LaserBendingFinishing | - |
| Jones & Lockhart Fabrication LLC Bending, Welding | St. Louis, MO | BendingWelding | - |
| Jonesboro Tool & Die Co Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding · AS9100, ITAR, CMMC | Jonesboro, AR | MillingTurningLaserWaterjetBendingWeldingStampingEDMGrinding | AS9100, ITAR, CMMC |
| K & E Plastics Inc Milling, Turning, Swiss, Bending · ISO 9001, ITAR | Bennington, VT | MillingTurningSwissBending | ISO 9001, ITAR |
| Kammerer Dynamics Inc Laser, Bending, Welding, Casting, Finishing, Assembly | Kendallville, IN | LaserBendingWeldingCastingFinishingAssembly | - |
| KB Sheetmetal Fabrication, Inc Turning, Bending, Welding, Finishing · ISO 9001 | Fountain Valley, CA | TurningBendingWeldingFinishing | ISO 9001 |
| Kencoa Aerospace LLC Milling, Turning, Waterjet, Punching, Bending, Welding, Stamping · AS9100, ITAR | Eastman, GA | MillingTurningWaterjetPunchingBendingWeldingStamping | AS9100, ITAR |
| Kern Steel Fabrication Inc Bending, Welding · ISO 9001 | Bakersfield, CA | BendingWelding | ISO 9001 |
| Kinney Manufacturing, LLC Bending, Laser, Welding, Metal AM | Lincoln, NE | BendingLaserWeldingMetal AM | - |
| L. E. F., Inc Milling, Laser, Bending, Welding, Stamping, Finishing | Tulsa, OK | MillingLaserBendingWeldingStampingFinishing | - |
| L.a. Martin Company Milling, Turning, Bending, Welding, Grinding, Finishing · ISO 9001 | Dearborn, MI | MillingTurningBendingWeldingGrindingFinishing | ISO 9001 |
| La Follette Machine & Tool Company, Inc Laser, Bending · ISO 9001 | La Follette, TN | LaserBending | ISO 9001 |
| Lasasco Inc Punching, Bending, Welding | Boise, ID | PunchingBendingWelding | - |
| Laser Precision Cutting Inc Laser, Waterjet, Bending, Welding, Finishing | Weaverville, NC | LaserWaterjetBendingWeldingFinishing | - |
| 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 |
| Lathrom Manufacturing Inc Milling, Turning, Bending, Grinding · ISO 9001, ITAR | Wichita, KS | MillingTurningBendingGrinding | ISO 9001, ITAR |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| Lee Precision Machine Shop Inc. Milling, Turning, Bending, Welding, EDM · ISO 9001, ITAR | Athens, AL | MillingTurningBendingWeldingEDM | ISO 9001, ITAR |
| Lewis Precision & CNC Inc Milling, Turning, Bending, Welding, Grinding, Finishing · ISO 9001, AS9100 | Theodore, AL | MillingTurningBendingWeldingGrindingFinishing | ISO 9001, AS9100 |
| Lima Sheet Metal Machine and Mfg., Inc Turning, Bending, Welding, Grinding | Lima, OH | TurningBendingWeldingGrinding | - |
| Lively Machine Milling, Turning, Bending, Finishing | Evansville, IN | MillingTurningBendingFinishing | - |
| LJ Fabricators, Inc. Bending, Laser, Welding · ISO 9001 | Rockford, IL | BendingLaserWelding | ISO 9001 |
| Luna's Sheet Metal Inc Milling, Turning, Bending, Laser, Welding | Santa Clara, CA | MillingTurningBendingLaserWelding | - |
| Lynchburg Machining, LLC Milling, Turning, Waterjet, Bending, Welding, EDM · ISO 9001 | Lynchburg, VA | MillingTurningWaterjetBendingWeldingEDM | ISO 9001 |
| M & M Sheet Metal, Inc Milling, Laser, Bending, Welding, Forging · ISO 9001, ITAR, CMMC | Williamsport, PA | MillingLaserBendingWeldingForging | ISO 9001, ITAR, CMMC |
| M & S Machining Inc Milling, Turning, Bending, Welding, EDM, Assembly · ISO 9001, AS9100, ITAR | Winchester, KY | MillingTurningBendingWeldingEDMAssembly | ISO 9001, AS9100, ITAR |
| M 7 Technologies Bending, Welding · ISO 9001 | Youngstown, OH | BendingWelding | ISO 9001 |
| M.a. Metal Co., Inc Laser, Bending, Welding, Stamping, Assembly · ISO 9001 | Columbus, IN | LaserBendingWeldingStampingAssembly | ISO 9001 |
| 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 Services Turning, Bending, EDM | Spokane, WA | TurningBendingEDM | - |
| 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 |
| Make + SHift atx Bending | Austin, TX | Bending | - |
| Mark One Metal Works Turning, Bending, Welding | Sparks, NV | TurningBendingWelding | - |
| Massie Mfg Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Finishing · ITAR | Baraga, MI | MillingTurningLaserWaterjetBendingWeldingFinishing | ITAR |
| Master Machine, Inc Milling, Turning, Bending, Casting · ISO 9001 | Minneapolis, MN | MillingTurningBendingCasting | ISO 9001 |
| Max Machining LLC Milling, Turning, Laser, Bending · ITAR, CMMC | Telford, PA | MillingTurningLaserBending | ITAR, CMMC |
| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| Maynard Inc Bending, Welding · ISO 9001, AS9100, ITAR, NADCAP | Fayetteville, AR | BendingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| McKenna Metal Bending, Laser, Welding, Waterjet | Portland, OR | BendingLaserWeldingWaterjet | - |
| Melton Sheet Metal Bending, Welding | Fresno, CA | BendingWelding | - |
| Menze Precision Machining, LLC Milling, Turning, Bending, Welding, EDM, Grinding, Finishing | Winter Haven, FL | MillingTurningBendingWeldingEDMGrindingFinishing | - |
| Met International Trading Company, Inc Laser, Punching, Bending, Welding, Finishing | Houston, TX | LaserPunchingBendingWeldingFinishing | - |
| Metal Components LLC Turning, Waterjet, Bending, Welding, Finishing, Assembly · ISO 9001 | Grand Rapids, MI | TurningWaterjetBendingWeldingFinishingAssembly | ISO 9001 |
| Metal Man Milling, Waterjet, Bending, Welding | Watertown, NY | MillingWaterjetBendingWelding | - |
| Metal Masterminds Laser, Waterjet, Punching, Bending, Welding, Stamping | Fountain Valley, CA | LaserWaterjetPunchingBendingWeldingStamping | - |
| Metalmasters Milling, Turning, Bending, Welding, Finishing | Brighton, CO | MillingTurningBendingWeldingFinishing | - |