| Ki Machine Tools & Productions Inc Milling, Turning, Bending, Welding, EDM, Grinding | Loves Park, IL | MillingTurningBendingWeldingEDMGrinding | - |
| King Tek EDM & Precision Machining Milling, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, NADCAP | Anaheim, CA | MillingBendingWeldingEDM | ISO 9001, AS9100, ITAR, NADCAP |
| L. E. F., Inc Milling, Laser, Bending, Welding, Stamping, Finishing | Tulsa, OK | MillingLaserBendingWeldingStampingFinishing | - |
| Laciny Brothers., Inc. Bending, Welding, Waterjet | St. Louis, MO | BendingWeldingWaterjet | - |
| Lacross Enterprises Inc Turning, Laser, Punching, Bending, Welding | Louisville, KY | TurningLaserPunchingBendingWelding | - |
| Lasasco Inc Punching, Bending, Welding | Boise, ID | PunchingBendingWelding | - |
| Laser Craft Technologies Inc Milling, Turning, Laser, Punching, Bending, Welding, Assembly · ISO 9001 | Gainesville, GA | MillingTurningLaserPunchingBendingWeldingAssembly | ISO 9001 |
| Laserform & Machine Inc Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Columbia, SC | TurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Laserworx Mfg Laser, Bending, Welding, Stamping · AS9100, ITAR | Oxnard, CA | LaserBendingWeldingStamping | AS9100, ITAR |
| 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 |
| Leiss Tool & Die Co Milling, Turning, Bending, Welding, Stamping, EDM, Grinding | Somerset, PA | MillingTurningBendingWeldingStampingEDMGrinding | - |
| Lively Machine Milling, Turning, Bending, Finishing | Evansville, IN | MillingTurningBendingFinishing | - |
| Logan Machine Co Milling, Turning, Bending, Welding | Akron, OH | MillingTurningBendingWelding | - |
| Lomar Machine & Tool Co Milling, Turning, Laser, Bending, Welding, Casting, EDM, Grinding, Finishing · ISO 9001 | Horton, MI | MillingTurningLaserBendingWeldingCastingEDMGrindingFinishing | ISO 9001 |
| Luna's Sheet Metal Inc Milling, Turning, Bending, Laser, Welding | Santa Clara, CA | MillingTurningBendingLaserWelding | - |
| M & S Machining Inc Milling, Turning, Bending, Welding, EDM, Assembly · ISO 9001, AS9100, ITAR | Winchester, KY | MillingTurningBendingWeldingEDMAssembly | ISO 9001, AS9100, ITAR |
| M&M Full Service Machine Shop Milling, Bending, Welding, Grinding, Finishing | Satellite Beach, FL | MillingBendingWeldingGrindingFinishing | - |
| Magnum Steel Works Milling, Turning, Waterjet, Bending, Welding | Mount Vernon, IL | MillingTurningWaterjetBendingWelding | - |
| 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 | - |
| Malone Industrial Machine, L.L.C Milling, Turning, Laser, Bending, Welding | Deer Park, TX | MillingTurningLaserBendingWelding | - |
| Mark One Metal Works Turning, Bending, Welding | Sparks, NV | TurningBendingWelding | - |
| Marsan Inc Bending, Welding, Assembly · ISO 9001 | Germantown, WI | BendingWeldingAssembly | ISO 9001 |
| Massie Mfg Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Finishing · ITAR | Baraga, MI | MillingTurningLaserWaterjetBendingWeldingFinishing | ITAR |
| Master Metal Products Co Bending, Welding | San Jose, CA | BendingWelding | - |
| Maynard Inc Bending, Welding · ISO 9001, AS9100, ITAR, NADCAP | Fayetteville, AR | BendingWelding | ISO 9001, AS9100, ITAR, NADCAP |
| MCW Certified Welding Ltd Punching, Bending, Welding | Delta, OH | PunchingBendingWelding | - |
| Mecha Inc Milling, Bending, Welding, Waterjet · ISO 9001, ITAR, NADCAP | Raleigh, NC | MillingBendingWeldingWaterjet | ISO 9001, ITAR, NADCAP |
| Megla Manufacturing, Inc. Milling, Bending, Laser, Welding, Waterjet | National City, CA | MillingBendingLaserWeldingWaterjet | - |
| Melton Sheet Metal Bending, Welding | Fresno, CA | BendingWelding | - |
| Metal Man Milling, Waterjet, Bending, Welding | Watertown, NY | MillingWaterjetBendingWelding | - |
| Metal Pro, Inc. Milling, Bending, Welding | Phoenix, AZ | MillingBendingWelding | - |
| Metalcraft Creative Bending, Laser, Welding | Birmingham, AL | BendingLaserWelding | - |
| Metalcraft Inc Bending, Laser, Welding | Boise, ID | BendingLaserWelding | - |
| Metaltech Inc Laser, Bending, Welding, Assembly · AS9100 | Auburn, WA | LaserBendingWeldingAssembly | AS9100 |
| Metalworking Group Bending, Welding · CMMC, ISO 9001, ITAR | Cincinnati, OH | BendingWelding | CMMC, ISO 9001, ITAR |
| Metplas Inc Milling, Turning, Waterjet, Punching, Bending, Assembly · ISO 9001 | Natrona Heights, PA | MillingTurningWaterjetPunchingBendingAssembly | ISO 9001 |
| Micro Metals Inc Milling, Laser, Waterjet, Punching, Bending, Welding | Colorado Springs, CO | MillingLaserWaterjetPunchingBendingWelding | - |
| Mid-State Metals Bending, Welding | Orlando, FL | BendingWelding | - |
| Midlake Products & Mfg. Co., Inc Turning, Bending, Laser, Welding, Stamping | Canton, OH | TurningBendingLaserWeldingStamping | - |
| Midwest Tool Inc. Milling, Bending, Welding | Chicago, IL | MillingBendingWelding | - |
| Millennium Metalcraft, Inc Milling, Laser, Bending, Welding, Finishing, Assembly · ISO 9001 | Fremont, CA | MillingLaserBendingWeldingFinishingAssembly | ISO 9001 |
| Millwood Metalworks Punching, Bending, Welding | Freeport, MN | PunchingBendingWelding | - |
| Milton Manufacturing, Inc Turning, Bending, Welding, Stamping, Assembly · ITAR | Detroit, MI | TurningBendingWeldingStampingAssembly | ITAR |
| Mission Critical Solutions LLC Milling, Punching, Bending, Welding | Alum Bank, PA | MillingPunchingBendingWelding | - |
| MM Industries Tech LLC Laser, Punching, Bending, Welding, Assembly | Stanwood, WA | LaserPunchingBendingWeldingAssembly | - |
| Motion Metalworks LLC Laser, Waterjet, Bending, Welding, Finishing | Wrens, GA | LaserWaterjetBendingWeldingFinishing | - |
| MRW Fabrication LLC Bending, Welding | Independence, MO | BendingWelding | - |