| Lektron Inc Milling, EDM, Assembly | Hartselle, AL | MillingEDMAssembly | - |
| Lenson Machine Inc Milling, Turning, Stamping, EDM · ISO 9001 | Middle River, MD | MillingTurningStampingEDM | ISO 9001 |
| LHM Engineering LLC Milling, Swiss, Laser, Waterjet, Stamping, EDM, Grinding, Finishing, Assembly · ISO 13485 | Manchester, MA | MillingSwissLaserWaterjetStampingEDMGrindingFinishingAssembly | ISO 13485 |
| Liberty Precision Works Inc Milling, Turning, EDM, Grinding | Tempe, AZ | MillingTurningEDMGrinding | - |
| Limestone Manufacturing LLC Milling, Turning, Laser, Bending, Welding, Metal AM, EDM, Grinding · ISO 9001, AS9100 | Somerset, KY | MillingTurningLaserBendingWeldingMetal AMEDMGrinding | ISO 9001, AS9100 |
| Linear Machining Technology LLC Milling, Turning, EDM, Grinding, Finishing · ISO 9001 | Irwin, PA | MillingTurningEDMGrindingFinishing | ISO 9001 |
| Loughmiller Machine, Tool & Design Milling, Turning, Waterjet, Welding, EDM, Finishing | Loogootee, IN | MillingTurningWaterjetWeldingEDMFinishing | - |
| Lynchburg Machining, LLC Milling, Turning, Waterjet, Bending, Welding, EDM · ISO 9001 | Lynchburg, VA | MillingTurningWaterjetBendingWeldingEDM | ISO 9001 |
| M & J Manufacturing, Inc. Milling, Turning, EDM | Portland, OR | MillingTurningEDM | - |
| M & S Machining Inc Milling, Turning, Bending, Welding, EDM, Assembly · ISO 9001, AS9100, ITAR | Winchester, KY | MillingTurningBendingWeldingEDMAssembly | ISO 9001, AS9100, ITAR |
| M-Tech Machining LLC Milling, Turning, EDM · ITAR | Edgewood, NM | MillingTurningEDM | ITAR |
| Mach Machine Inc Turning, Welding, Stamping, Casting, EDM, Assembly · ISO 9001, ITAR | Hudson, MA | TurningWeldingStampingCastingEDMAssembly | ISO 9001, ITAR |
| Machine Tech Inc Milling, Turning, EDM · ISO 9001 | Houma, LA | MillingTurningEDM | ISO 9001 |
| Machine Tool Services Turning, Bending, EDM | Spokane, WA | TurningBendingEDM | - |
| Machine Tool Technology LLC Milling, EDM | South Chesterfield, VA | MillingEDM | - |
| Machine Works, L.L.C Milling, Turning, EDM, Grinding · ISO 9001, ITAR | Phoenix, AZ | MillingTurningEDMGrinding | ISO 9001, ITAR |
| Machining Tech Milling, Turning, Waterjet, Welding, Stamping, EDM, Grinding | Hazle Township, PA | MillingTurningWaterjetWeldingStampingEDMGrinding | - |
| Machinist Lab Milling, EDM | San Diego, CA | MillingEDM | - |
| Machinists Inc Milling, Turning, Laser, Welding, EDM, Grinding · ISO 9001, ITAR | Seattle, WA | MillingTurningLaserWeldingEDMGrinding | ISO 9001, ITAR |
| Magnolia Machine Company Milling, Turning, Welding, EDM, Grinding | Auburndale, FL | MillingTurningWeldingEDMGrinding | - |
| Manda Machine Co Milling, Turning, Laser, Welding, Waterjet, EDM · ISO 9001, AS9100 | Dallas, TX | MillingTurningLaserWeldingWaterjetEDM | ISO 9001, AS9100 |
| Manor Tool & Manufacturing Co Milling, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001, ITAR | Schiller Park, IL | MillingLaserWaterjetBendingWeldingStampingEDMGrindingFinishing | ISO 9001, ITAR |
| Marion Manufacturing Milling, Turning, Welding, Stamping, EDM · AS9100 | West Terre Haute, IN | MillingTurningWeldingStampingEDM | AS9100 |
| Marion Manufacturing Co Inc Milling, Turning, Laser, Stamping, EDM | Cheshire, CT | MillingTurningLaserStampingEDM | - |
| Marion Mold & Tool Inc Milling, Turning, Waterjet, EDM, Grinding · ISO 9001, AS9100 | Marion, VA | MillingTurningWaterjetEDMGrinding | ISO 9001, AS9100 |
| Mars Engineering Milling, Turning, Waterjet, EDM, Grinding, Finishing, Assembly | San Leandro, CA | MillingTurningWaterjetEDMGrindingFinishingAssembly | - |
| Marton Precision MF Milling, Turning, Waterjet, Welding, EDM, Finishing · ISO 9001, AS9100, ITAR | Fullerton, CA | MillingTurningWaterjetWeldingEDMFinishing | ISO 9001, AS9100, ITAR |
| Marvel Manufacturing Milling, Turning, Swiss, Welding, EDM, Grinding, Finishing | Lewiston, ID | MillingTurningSwissWeldingEDMGrindingFinishing | - |
| Maumee Pattern Co Milling, Turning, Casting, EDM · ITAR, CMMC | Toledo, OH | MillingTurningCastingEDM | ITAR, CMMC |
| MBK Machine Corp Milling, Turning, Laser, EDM, Grinding · ITAR | Mead, CO | MillingTurningLaserEDMGrinding | ITAR |
| McGinley Manufacturing Milling, Turning, Swiss, Welding, EDM · ISO 13485 | Glenrock, WY | MillingTurningSwissWeldingEDM | ISO 13485 |
| McKenzie Machining Inc Milling, Turning, EDM, Grinding · ISO 9001, AS9100, ITAR | San Jose, CA | MillingTurningEDMGrinding | ISO 9001, AS9100, ITAR |
| McQuillen Manufacturing LLC Milling, EDM · ISO 9001, AS9100, ITAR | Honeoye Falls, NY | MillingEDM | ISO 9001, AS9100, ITAR |
| Mean Machine LLC Milling, Turning, EDM | Logan, UT | MillingTurningEDM | - |
| Menze Precision Machining, LLC Milling, Turning, Bending, Welding, EDM, Grinding, Finishing | Winter Haven, FL | MillingTurningBendingWeldingEDMGrindingFinishing | - |
| Mercer Machine Company, Inc Milling, Turning, EDM · AS9100 | Camby, IN | MillingTurningEDM | AS9100 |
| Meridian Manufacturing Inc Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Ballston Spa, NY | MillingTurningLaserWeldingEDMGrindingFinishing | - |
| Meta-Tech Industries, Inc Milling, Turning, Welding, EDM, Finishing · ISO 9001 | Houston, TX | MillingTurningWeldingEDMFinishing | ISO 9001 |
| Metalogic Industries LLC Milling, Turning, Swiss, Laser, Welding, EDM, Grinding | Southbridge, MA | MillingTurningSwissLaserWeldingEDMGrinding | - |
| MFC Netform LLC Milling, Laser, Waterjet, Bending, Welding, Stamping, Forging, EDM, Grinding · ISO 9001, IATF 16949 | Shelby Township, MI | MillingLaserWaterjetBendingWeldingStampingForgingEDMGrinding | ISO 9001, IATF 16949 |
| Michigan CNC Tool, Inc Milling, Turning, EDM, Grinding · ISO 9001 | Whitmore Lake, MI | MillingTurningEDMGrinding | ISO 9001 |
| Micron Precision Machining Inc Milling, Turning, EDM, Grinding | Saginaw, MI | MillingTurningEDMGrinding | - |
| Midway Machine & Instrument Company Inc Milling, Turning, EDM, Finishing · ISO 9001 | South Houston, TX | MillingTurningEDMFinishing | ISO 9001 |
| Midwest Tool Inc Milling, Turning, Welding, EDM, Grinding | Joplin, MO | MillingTurningWeldingEDMGrinding | - |
| Modern Machine Works Milling, Turning, Welding, EDM, Grinding, Finishing | Albany, OR | MillingTurningWeldingEDMGrindingFinishing | - |
| Mono Engineering Corp Turning, Welding, EDM · ISO 9001 | Chatsworth, CA | TurningWeldingEDM | ISO 9001 |
| Monsees Tool & Die Inc Milling, Turning, EDM, Grinding, Finishing | Rochester, NY | MillingTurningEDMGrindingFinishing | - |
| Morehead Machinery Inc Milling, Turning, Welding, EDM, Grinding | Elkhart, IN | MillingTurningWeldingEDMGrinding | - |
| Mountain Defense LLC Milling, Turning, EDM, Assembly | Mentor, OH | MillingTurningEDMAssembly | - |
| Mountain Precision Tool Co, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, EDM, Grinding, Finishing | Blacksburg, VA | MillingTurningLaserWaterjetPunchingBendingWeldingEDMGrindingFinishing | - |