| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| McAlpin Industries Inc. Milling, Bending, Laser, Welding, Stamping | Rochester, NY | MillingBendingLaserWeldingStamping | - |
| McCallin Steel Storage Systems, Inc Milling, Punching, Welding, Finishing | Commerce City, CO | MillingPunchingWeldingFinishing | - |
| McCormick Industries Inc Milling, Turning, Swiss, Welding, Grinding, Finishing, Assembly · ISO 9001 | Appleton, WI | MillingTurningSwissWeldingGrindingFinishingAssembly | ISO 9001 |
| McKenzie Machining Inc Milling, Turning, EDM, Grinding · ISO 9001, AS9100, ITAR | San Jose, CA | MillingTurningEDMGrinding | ISO 9001, AS9100, ITAR |
| Mechfi Designs LLC Milling, Turning, Finishing | Westminster, CO | MillingTurningFinishing | - |
| Medical Micro Machining Inc Milling | Colfax, WA | Milling | - |
| Mega Precision LLC Milling, Turning · ISO 9001, AS9100 | Newington, CT | MillingTurning | ISO 9001, AS9100 |
| Megla Manufacturing, Inc. Milling, Bending, Laser, Welding, Waterjet | National City, CA | MillingBendingLaserWeldingWaterjet | - |
| Mennie's Machine Co Milling, Turning, Welding, Grinding · IATF 16949 | Mark, IL | MillingTurningWeldingGrinding | IATF 16949 |
| Menze Precision Machining, LLC Milling, Turning, Bending, Welding, EDM, Grinding, Finishing | Winter Haven, FL | MillingTurningBendingWeldingEDMGrindingFinishing | - |
| Mercury Aircraft Inc Milling, Laser, Punching, Bending, Welding, Stamping, Assembly · ISO 9001, AS9100, ITAR | Hammondsport, NY | MillingLaserPunchingBendingWeldingStampingAssembly | ISO 9001, AS9100, ITAR |
| Mercury Machine Works LLC Milling, Turning, Laser, Finishing · ISO 9001, ITAR | Spring, TX | MillingTurningLaserFinishing | ISO 9001, ITAR |
| Mercury Machining Co Milling, Turning, Welding, Grinding | Pensacola, FL | MillingTurningWeldingGrinding | - |
| Meridian Industrial Group, LLC Milling, Turning, Welding, Casting · ISO 9001, AS9100 | Holyoke, MA | MillingTurningWeldingCasting | ISO 9001, AS9100 |
| Meridian Manufacturing Inc Milling, Turning, Laser, Welding, EDM, Grinding, Finishing | Ballston Spa, NY | MillingTurningLaserWeldingEDMGrindingFinishing | - |
| Merritt Preferred Components Inc Milling, Turning, Waterjet, Grinding | Kilgore, TX | MillingTurningWaterjetGrinding | - |
| Meta Manufacturing Corp Milling, Turning | Blue Ash, OH | MillingTurning | - |
| Metal Arts Machine Co. Milling · ISO 9001, AS9100, ITAR, NADCAP | Wichita, KS | Milling | ISO 9001, AS9100, ITAR, NADCAP |
| Metal Essence Inc Milling, Turning, Swiss, Finishing, Assembly · ISO 9001, AS9100, ITAR | Longwood, FL | MillingTurningSwissFinishingAssembly | ISO 9001, AS9100, ITAR |
| Metal Fusion Inc Milling, Turning, Welding, Grinding | Redwood City, CA | MillingTurningWeldingGrinding | - |
| Metal Industries, Inc Milling, Turning, Welding | Hartford, CT | MillingTurningWelding | - |
| Metal Man Milling, Waterjet, Bending, Welding | Watertown, NY | MillingWaterjetBendingWelding | - |
| Metal Pro, Inc. Milling, Bending, Welding | Phoenix, AZ | MillingBendingWelding | - |
| Metal Works Precision Machine and Tool, Inc Milling, Turning, Welding | Tucson, AZ | MillingTurningWelding | - |
| Metal Workz L.L.C Milling, Turning, Laser, Bending, Welding, Finishing | Albany, KY | MillingTurningLaserBendingWeldingFinishing | - |
| Metalbuilt LLC Milling, Turning, Laser, Welding, Stamping, Finishing · ISO 9001, AS9100, IATF 16949 | Chesterfield, MI | MillingTurningLaserWeldingStampingFinishing | ISO 9001, AS9100, IATF 16949 |
| Metalid Manufacturing Inc Milling · ISO 9001 | Pacoima, CA | Milling | ISO 9001 |
| Metalmasters Milling, Turning, Bending, Welding, Finishing | Brighton, CO | MillingTurningBendingWeldingFinishing | - |
| Metalquest Unlimited, Inc Milling, Turning, Finishing, Assembly | Hebron, NE | MillingTurningFinishingAssembly | - |
| Metro Machine Inc Milling, Turning, Grinding · ISO 9001, AS9100, ITAR | Englewood, CO | MillingTurningGrinding | ISO 9001, AS9100, ITAR |
| Metron Machining LLC Milling, Metal AM · AS9100, ITAR, CMMC | Lakewood, CO | MillingMetal AM | AS9100, ITAR, CMMC |
| Meyer Tool & Manufacturing, Inc Milling, Turning, Welding · ITAR | Oak Lawn, IL | MillingTurningWelding | ITAR |
| MF Engineering Company, Inc Milling, Turning, Swiss, Welding, Grinding, Finishing · ISO 9001, NADCAP | Bristol, RI | MillingTurningSwissWeldingGrindingFinishing | ISO 9001, NADCAP |
| MFC Netform LLC Milling, Laser, Waterjet, Bending, Welding, Stamping, Forging, EDM, Grinding · ISO 9001, IATF 16949 | Shelby Township, MI | MillingLaserWaterjetBendingWeldingStampingForgingEDMGrinding | ISO 9001, IATF 16949 |
| Micar Fabrication Milling, Turning, Welding | Las Vegas, NV | MillingTurningWelding | - |
| Mico Welding & Machining, Inc Milling, Turning, Welding, Finishing | Nine Mile Falls, WA | MillingTurningWeldingFinishing | - |
| Micro Facture LLC Milling, Turning, EDM, Grinding, Assembly · ISO 9001, ITAR | Lancaster, PA | MillingTurningEDMGrindingAssembly | ISO 9001, ITAR |
| Micro Precision, LLC Milling · ISO 9001 | South Windham, CT | Milling | ISO 9001 |
| Micro-Matics Inc Milling, Turning, Swiss, Casting, EDM, Grinding, Assembly | Fridley, MN | MillingTurningSwissCastingEDMGrindingAssembly | - |
| Micro-Tec, Inc Milling, Turning, Welding, EDM, Finishing · ISO 9001, AS9100 | Chatsworth, CA | MillingTurningWeldingEDMFinishing | ISO 9001, AS9100 |
| Micron Manufacturing Company Milling, Turning · ISO 9001 | Grand Rapids, MI | MillingTurning | ISO 9001 |
| Microwave Components Specialists, Inc Milling, Turning | Orleans, MA | MillingTurning | - |
| Mid America Steel Inc Milling, Bending, Welding, Casting | Fargo, ND | MillingBendingWeldingCasting | - |
| Mid-Continent Machining Inc Milling, Turning, Welding, Finishing | Kansas City, KS | MillingTurningWeldingFinishing | - |
| Midway Machine & Instrument Company Inc Milling, Turning, EDM, Finishing · ISO 9001 | South Houston, TX | MillingTurningEDMFinishing | ISO 9001 |
| Midway Swiss Turn, Inc Milling, Turning, Swiss, Finishing, Assembly · CMMC | Wooster, OH | MillingTurningSwissFinishingAssembly | CMMC |
| Midwest Metal Fabrications Milling, Turning, Bending, Laser, Welding · ISO 9001, AS9100 | Tallmadge, OH | MillingTurningBendingLaserWelding | ISO 9001, AS9100 |
| Midwest Precision LLC Milling, Turning, Casting, EDM, Grinding, Assembly · ISO 9001, ITAR | Eastlake, OH | MillingTurningCastingEDMGrindingAssembly | ISO 9001, ITAR |
| Mikelson Machine Shop, Inc Milling, Turning | S El Monte, CA | MillingTurning | - |