| Kiski Precision Industries, LLC Milling, Turning, Welding, Assembly | Leechburg, PA | MillingTurningWeldingAssembly | - |
| KSM Industries Inc Bending, Welding, Assembly | Germantown, WI | BendingWeldingAssembly | - |
| Lark Industries Turning, Waterjet, Welding, Assembly · ISO 9001, ISO 13485 | El Paso, TX | TurningWaterjetWeldingAssembly | ISO 9001, ISO 13485 |
| Leanwerks, LLC Milling, Turning, Welding, Casting, Grinding, Assembly · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningWeldingCastingGrindingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Lektron Inc Milling, EDM, Assembly | Hartselle, AL | MillingEDMAssembly | - |
| LHM Engineering LLC Milling, Swiss, Laser, Waterjet, Stamping, EDM, Grinding, Finishing, Assembly · ISO 13485 | Manchester, MA | MillingSwissLaserWaterjetStampingEDMGrindingFinishingAssembly | ISO 13485 |
| Lightning Aerospace LLC Milling, Turning, Bending, Assembly · ISO 9001, AS9100, ITAR | Park City, KS | MillingTurningBendingAssembly | ISO 9001, AS9100, ITAR |
| Lincoln Tool & Machine Corp Milling, Assembly | Hudson, MA | MillingAssembly | - |
| Linita Design & Mfg. Corp Turning, Welding, Assembly | Lackawanna, NY | TurningWeldingAssembly | - |
| M & S Machining Inc Milling, Turning, Bending, Welding, EDM, Assembly · ISO 9001, AS9100, ITAR | Winchester, KY | MillingTurningBendingWeldingEDMAssembly | ISO 9001, AS9100, ITAR |
| Mac Products, Inc Milling, Waterjet, Bending, Welding, Assembly · ISO 9001 | Kearny, NJ | MillingWaterjetBendingWeldingAssembly | ISO 9001 |
| Mach Machine Inc Turning, Welding, Stamping, Casting, EDM, Assembly · ISO 9001, ITAR | Hudson, MA | TurningWeldingStampingCastingEDMAssembly | ISO 9001, ITAR |
| Machine Incorporated Milling, Turning, Swiss, Assembly · ISO 9001, AS9100 | Stoughton, MA | MillingTurningSwissAssembly | ISO 9001, AS9100 |
| Machine Repair & Design Milling, Turning, Waterjet, Welding, Finishing, Assembly · AS9100 | Sumner, WA | MillingTurningWaterjetWeldingFinishingAssembly | AS9100 |
| Manufacture.us Milling, Turning, Swiss, Laser, Finishing, Assembly | Doral, FL | MillingTurningSwissLaserFinishingAssembly | - |
| Mars Engineering Milling, Turning, Waterjet, EDM, Grinding, Finishing, Assembly | San Leandro, CA | MillingTurningWaterjetEDMGrindingFinishingAssembly | - |
| Marsan Inc Bending, Welding, Assembly · ISO 9001 | Germantown, WI | BendingWeldingAssembly | ISO 9001 |
| Mason Dixon Fabrication LLC Milling, Turning, Welding, Assembly | Hanover, PA | MillingTurningWeldingAssembly | - |
| Mass Precision Inc Welding, Assembly · ISO 9001, ISO 13485 | San Jose, CA | WeldingAssembly | ISO 9001, ISO 13485 |
| McCormick Industries Inc Milling, Turning, Swiss, Welding, Grinding, Finishing, Assembly · ISO 9001 | Appleton, WI | MillingTurningSwissWeldingGrindingFinishingAssembly | ISO 9001 |
| McNeil Industries Inc Milling, Turning, Welding, Stamping, Grinding, Assembly · ISO 9001, AS9100 | Painesville, OH | MillingTurningWeldingStampingGrindingAssembly | ISO 9001, AS9100 |
| Mdi Manufacturing Inc Milling, Turning, Welding, Grinding, Assembly · ISO 9001 | Lakewood, NJ | MillingTurningWeldingGrindingAssembly | ISO 9001 |
| Menco LLC Welding, Assembly | Wallace, MI | WeldingAssembly | - |
| Metal Essence Inc Milling, Turning, Swiss, Finishing, Assembly · ISO 9001, AS9100, ITAR | Longwood, FL | MillingTurningSwissFinishingAssembly | ISO 9001, AS9100, ITAR |
| Metalcraft Industries, Inc Welding, Stamping, Finishing, Assembly · CMMC | Denver, CO | WeldingStampingFinishingAssembly | CMMC |
| Metalcrafters, Inc Stamping, Assembly · ISO 9001, ITAR | Methuen, MA | StampingAssembly | ISO 9001, ITAR |
| Metalquest Unlimited, Inc Milling, Turning, Finishing, Assembly | Hebron, NE | MillingTurningFinishingAssembly | - |
| Micro Machine & Electronics, Inc Milling, Turning, Welding, Grinding, Finishing, Assembly · ITAR | Leominster, MA | MillingTurningWeldingGrindingFinishingAssembly | ITAR |
| Middletown Industrial Technologies, LLC Milling, Turning, Welding, Stamping, Assembly | Middletown, OH | MillingTurningWeldingStampingAssembly | - |
| Midway Swiss Turn, Inc Milling, Turning, Swiss, Finishing, Assembly · CMMC | Wooster, OH | MillingTurningSwissFinishingAssembly | CMMC |
| Mikron Manufacturing Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Colorado Springs, CO | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| Millrite Machine Inc Turning, Assembly · ISO 9001 | Westfield, MA | TurningAssembly | ISO 9001 |
| Milton Manufacturing, Inc Turning, Bending, Welding, Stamping, Assembly · ITAR | Detroit, MI | TurningBendingWeldingStampingAssembly | ITAR |
| MM Industries Tech LLC Laser, Punching, Bending, Welding, Assembly | Stanwood, WA | LaserPunchingBendingWeldingAssembly | - |
| Modus Advanced Milling, Waterjet, Finishing, Assembly · ISO 9001, AS9100, ITAR, CMMC | Carlsbad, CA | MillingWaterjetFinishingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Monarch Valve Corp Milling, Turning, Welding, Grinding, Assembly · ISO 9001 | Aston, PA | MillingTurningWeldingGrindingAssembly | ISO 9001 |
| Morrison Industries LLC Milling, Turning, Laser, Bending, Welding, Finishing, Assembly | Morrison, TN | MillingTurningLaserBendingWeldingFinishingAssembly | - |
| Motive Machine Works LLC Milling, Turning, Stamping, Finishing, Assembly | Lancaster, PA | MillingTurningStampingFinishingAssembly | - |
| Mountain CNC Milling, Turning, Waterjet, Welding, Grinding, Finishing, Assembly · ITAR, CMMC | Loveland, CO | MillingTurningWaterjetWeldingGrindingFinishingAssembly | ITAR, CMMC |
| Mountain Defense LLC Milling, Turning, EDM, Assembly | Mentor, OH | MillingTurningEDMAssembly | - |
| Mountain Manufacturing, LLC Milling, Laser, Bending, Welding, Finishing, Assembly · ISO 13485 | Post Falls, ID | MillingLaserBendingWeldingFinishingAssembly | ISO 13485 |
| MSP Maufacturing Milling, Turning, Bending, Welding, Finishing, Assembly | Bloomington, IN | MillingTurningBendingWeldingFinishingAssembly | - |
| Multi-Machining Co Inc Milling, Turning, Finishing, Assembly | Greenville, TX | MillingTurningFinishingAssembly | - |
| O & Y Precision Inc Milling, Laser, Waterjet, Bending, Welding, EDM, Finishing, Assembly | Morgan Hill, CA | MillingLaserWaterjetBendingWeldingEDMFinishingAssembly | - |
| Octal Corporation Milling, Turning, Welding, Grinding, Assembly · ISO 9001, AS9100 | Teaneck, NJ | MillingTurningWeldingGrindingAssembly | ISO 9001, AS9100 |
| Omikron Engineering, Inc Milling, Turning, Swiss, Assembly · ISO 9001 | Chatsworth, CA | MillingTurningSwissAssembly | ISO 9001 |
| Onium Machine and Fabrication, LLC Milling, Turning, Laser, Bending, Welding, Assembly · ISO 9001 | Winder, GA | MillingTurningLaserBendingWeldingAssembly | ISO 9001 |
| Onodi Tool & Engineering Co Milling, Turning, Welding, Assembly · ISO 9001 | Melvindale, MI | MillingTurningWeldingAssembly | ISO 9001 |
| P & F Machining, Inc Milling, Swiss, Grinding, Assembly · ISO 9001, AS9100, ISO 13485 | Otsego, MN | MillingSwissGrindingAssembly | ISO 9001, AS9100, ISO 13485 |
| Paradigm Industrial Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Assembly · ISO 9001, ITAR, CMMC | Dayton, OH | MillingTurningWaterjetBendingWeldingEDMGrindingAssembly | ISO 9001, ITAR, CMMC |