| Jones Metal, Inc Milling, Laser, Waterjet, Bending, Welding, Finishing, Assembly | Mankato, MN | MillingLaserWaterjetBendingWeldingFinishingAssembly | - |
| Jonesboro Tool & Die Co Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding · AS9100, ITAR, CMMC | Jonesboro, AR | MillingTurningLaserWaterjetBendingWeldingStampingEDMGrinding | AS9100, ITAR, CMMC |
| JP Metal Fabrication, Inc. Milling, Bending, Laser, Welding | Santa Clara, CA | MillingBendingLaserWelding | - |
| Justified Performance LLC Laser, Bending, Welding, Finishing, Assembly · ISO 9001 | Rocklin, CA | LaserBendingWeldingFinishingAssembly | ISO 9001 |
| K&M Milling, Turning, Laser, Welding, Assembly · ISO 9001 | Cassopolis, MI | MillingTurningLaserWeldingAssembly | ISO 9001 |
| Kammerer Dynamics Inc Laser, Bending, Welding, Casting, Finishing, Assembly | Kendallville, IN | LaserBendingWeldingCastingFinishingAssembly | - |
| Kihm Metal Technologies Laser, Welding | Brazil, IN | LaserWelding | - |
| Kinney Manufacturing, LLC Bending, Laser, Welding, Metal AM | Lincoln, NE | BendingLaserWeldingMetal AM | - |
| Kinross Fab & Machine Inc Milling, Turning, Laser, Welding, Grinding, Finishing | Kincheloe, MI | MillingTurningLaserWeldingGrindingFinishing | - |
| Ko Laser Milling, Turning, Laser, Bending, Welding | Tulsa, OK | MillingTurningLaserBendingWelding | - |
| Kriewall Enterprises Inc Milling, Laser, Welding, Stamping, EDM, Finishing · ISO 9001 | Romeo, MI | MillingLaserWeldingStampingEDMFinishing | ISO 9001 |
| KV Engineering LLC Milling, Turning, Laser, Waterjet, Welding | Miami, FL | MillingTurningLaserWaterjetWelding | - |
| L. C. S. Co Laser, Welding, Stamping, EDM · ISO 9001, AS9100, ITAR, NADCAP | Saint Paul, MN | LaserWeldingStampingEDM | ISO 9001, AS9100, ITAR, NADCAP |
| L. E. F., Inc Milling, Laser, Bending, Welding, Stamping, Finishing | Tulsa, OK | MillingLaserBendingWeldingStampingFinishing | - |
| L&B Labs Milling, Turning, Laser, Welding, EDM, Grinding | San Jose, CA | MillingTurningLaserWeldingEDMGrinding | - |
| Lacross Enterprises Inc Turning, Laser, Punching, Bending, Welding | Louisville, KY | TurningLaserPunchingBendingWelding | - |
| Lai International Inc Milling, Laser, Waterjet, Welding, Metal AM, EDM, Finishing · NADCAP | Westminster, MD | MillingLaserWaterjetWeldingMetal AMEDMFinishing | NADCAP |
| Langley Industrial Machining Milling, Turning, Laser, Punching, Welding, Stamping, Finishing · ISO 9001 | Sharpsburg, NC | MillingTurningLaserPunchingWeldingStampingFinishing | ISO 9001 |
| Lanzen Inc Milling, Laser, Welding | Bruce Twp, MI | MillingLaserWelding | - |
| Laser Craft Technologies Inc Milling, Turning, Laser, Punching, Bending, Welding, Assembly · ISO 9001 | Gainesville, GA | MillingTurningLaserPunchingBendingWeldingAssembly | ISO 9001 |
| Laser Cutting Co Milling, Laser, Bending, Welding, Grinding, Finishing · ISO 9001 | Harrison Township, MI | MillingLaserBendingWeldingGrindingFinishing | ISO 9001 |
| Laser Metal Fabrication Laser, Bending, Welding, Assembly | Twin Falls, ID | LaserBendingWeldingAssembly | - |
| 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 |
| Laserworx Mfg Laser, Bending, Welding, Stamping · AS9100, ITAR | Oxnard, CA | LaserBendingWeldingStamping | AS9100, ITAR |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| Legacy Industries Laser, Welding, Stamping · ITAR | Auburn Hills, MI | LaserWeldingStamping | ITAR |
| Lehi Sheet Metal Turning, Laser, Punching, Bending, Welding, Grinding, Finishing · ISO 9001, AS9100, ITAR | Westborough, MA | TurningLaserPunchingBendingWeldingGrindingFinishing | ISO 9001, AS9100, ITAR |
| LG Metalworks LLC Milling, Turning, Laser, Waterjet, Welding, EDM, Finishing | Bloomington, IN | MillingTurningLaserWaterjetWeldingEDMFinishing | - |
| Limestone Manufacturing LLC Milling, Turning, Laser, Bending, Welding, Metal AM, EDM, Grinding · ISO 9001, AS9100 | Somerset, KY | MillingTurningLaserBendingWeldingMetal AMEDMGrinding | ISO 9001, AS9100 |
| Lindsay Machine Works, Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Grinding | Independence, MO | MillingTurningLaserWaterjetBendingWeldingGrinding | - |
| LLB Metal Fabrication Limited Liability Company Turning, Laser, Waterjet, Welding | Honolulu, HI | TurningLaserWaterjetWelding | - |
| Locdown Com Laser, Bending, Welding, Finishing | Brea, CA | LaserBendingWeldingFinishing | - |
| LR Design+Build Laser, Welding, Metal AM | Columbus, OH | LaserWeldingMetal AM | - |
| Luna's Sheet Metal Inc Milling, Turning, Bending, Laser, Welding | Santa Clara, CA | MillingTurningBendingLaserWelding | - |
| LX3 Tooling Milling, Turning, Laser, Welding, Grinding · CMMC | Aledo, TX | MillingTurningLaserWeldingGrinding | CMMC |
| M & M Sheet Metal, Inc Milling, Laser, Bending, Welding, Forging · ISO 9001, ITAR, CMMC | Williamsport, PA | MillingLaserBendingWeldingForging | ISO 9001, ITAR, CMMC |
| 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 | - |
| Machine & Tool Manufacturing Company Milling, Laser, Waterjet, Welding, Finishing | Adel, GA | MillingLaserWaterjetWeldingFinishing | - |
| Machineworks Manufacturing Milling, Turning, Laser, Bending, Welding, Finishing · ISO 9001, AS9100, ITAR | Northridge, CA | MillingTurningLaserBendingWeldingFinishing | ISO 9001, AS9100, ITAR |
| Machinists Inc Milling, Turning, Laser, Welding, EDM, Grinding · ISO 9001, ITAR | Seattle, WA | MillingTurningLaserWeldingEDMGrinding | ISO 9001, ITAR |
| 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 |
| Malone Industrial Machine, L.L.C Milling, Turning, Laser, Bending, Welding | Deer Park, TX | MillingTurningLaserBendingWelding | - |
| Manor Tool & Manufacturing Co Milling, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001, ITAR | Schiller Park, IL | MillingLaserWaterjetBendingWeldingStampingEDMGrindingFinishing | ISO 9001, ITAR |
| Massie Mfg Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Finishing · ITAR | Baraga, MI | MillingTurningLaserWaterjetBendingWeldingFinishing | ITAR |
| MaxFab Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly | Madison, AL | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | - |
| McAlpin Industries Inc. Milling, Bending, Laser, Welding, Stamping | Rochester, NY | MillingBendingLaserWeldingStamping | - |
| McKenna Metal Bending, Laser, Welding, Waterjet | Portland, OR | BendingLaserWeldingWaterjet | - |