| Independent Machine Company Milling, Turning, Laser, Welding, Grinding | Escanaba, MI | MillingTurningLaserWeldingGrinding | - |
| Industrial Sales & Manufacturing, Inc. Milling, Turning, Bending, Laser, Welding · ISO 9001 | Erie, PA | MillingTurningBendingLaserWelding | ISO 9001 |
| Infinity Precision Inc Milling, Turning, Waterjet, Bending, Grinding · ISO 9001, AS9100 | Simi Valley, CA | MillingTurningWaterjetBendingGrinding | ISO 9001, AS9100 |
| Inland Marine Industries Inc Milling, Turning, Waterjet, Punching, Bending, Welding, Grinding, Finishing · ISO 9001, ITAR | Hayward, CA | MillingTurningWaterjetPunchingBendingWeldingGrindingFinishing | ISO 9001, ITAR |
| Innovation Alley Milling, Turning, Bending, Welding | Fresno, CA | MillingTurningBendingWelding | - |
| Inter-Precision Mold Inc Milling, Turning, Welding, EDM, Grinding, Assembly | El Paso, TX | MillingTurningWeldingEDMGrindingAssembly | - |
| Iowa Metal Spinners Milling, Turning, Laser, Welding, Stamping · ISO 9001 | Cedar Falls, IA | MillingTurningLaserWeldingStamping | ISO 9001 |
| ISCO Manufacturing Solutions Milling, Turning, Waterjet, Bending, Welding, Grinding · ISO 9001, AS9100 | Bend, OR | MillingTurningWaterjetBendingWeldingGrinding | ISO 9001, AS9100 |
| J & P Khamken Industries Inc Milling, Turning, Waterjet, Bending, Welding · ISO 9001 | Montgomery, AL | MillingTurningWaterjetBendingWelding | ISO 9001 |
| J Mark Co Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Vista, CA | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| J W Machine & Fab LLC Milling, Turning, Welding, Grinding | Fountain Inn, SC | MillingTurningWeldingGrinding | - |
| JC Machine, Inc Milling, Turning, Swiss, Laser, Bending, Welding | Lakeland, FL | MillingTurningSwissLaserBendingWelding | - |
| JD Machine Milling, Turning, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningBendingWeldingEDM | ISO 9001, AS9100, ITAR, CMMC |
| Jeglinski Group Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001 | Meadville, PA | MillingTurningWeldingEDMGrindingAssembly | ISO 9001 |
| Jetfab LLC Milling, Turning, Laser, Waterjet, Punching, Bending, Welding | Lowell, MA | MillingTurningLaserWaterjetPunchingBendingWelding | - |
| Jones Co Machining Milling, Turning, Welding, Assembly | Hannibal, MO | MillingTurningWeldingAssembly | - |
| K&B Industries Turning, Assembly · ISO 9001 | Houma, LA | TurningAssembly | ISO 9001 |
| Kaskaskia Tool and Machine, Inc Milling, Turning, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | New Athens, IL | MillingTurningBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| Kencoa Aerospace LLC Milling, Turning, Waterjet, Punching, Bending, Welding, Stamping · AS9100, ITAR | Eastman, GA | MillingTurningWaterjetPunchingBendingWeldingStamping | AS9100, ITAR |
| Ketchie-Houston, Inc Milling, Turning, EDM, Grinding · ISO 9001, AS9100 | Concord, NC | MillingTurningEDMGrinding | ISO 9001, AS9100 |
| Ki Machine Tools & Productions Inc Milling, Turning, Bending, Welding, EDM, Grinding | Loves Park, IL | MillingTurningBendingWeldingEDMGrinding | - |
| Kinetik Systems LLC Milling, Turning, Welding | Tucson, AZ | MillingTurningWelding | - |
| Kinross Fab & Machine Inc Milling, Turning, Laser, Welding, Grinding, Finishing | Kincheloe, MI | MillingTurningLaserWeldingGrindingFinishing | - |
| Ko Laser Milling, Turning, Laser, Bending, Welding | Tulsa, OK | MillingTurningLaserBendingWelding | - |
| Krisalis Precision Machining Milling, Turning | San Andreas, CA | MillingTurning | - |
| Lacross Enterprises Inc Turning, Laser, Punching, Bending, Welding | Louisville, KY | TurningLaserPunchingBendingWelding | - |
| Lake Precision Machine Inc Turning, Welding | Hagerstown, MD | TurningWelding | - |
| Langley Industrial Machining Milling, Turning, Laser, Punching, Welding, Stamping, Finishing · ISO 9001 | Sharpsburg, NC | MillingTurningLaserPunchingWeldingStampingFinishing | ISO 9001 |
| Laser Craft Technologies Inc Milling, Turning, Laser, Punching, Bending, Welding, Assembly · ISO 9001 | Gainesville, GA | MillingTurningLaserPunchingBendingWeldingAssembly | ISO 9001 |
| Lear Machining & Waterjet Inc Milling, Turning, Waterjet, Welding, Grinding · ISO 9001 | Columbus, IN | MillingTurningWaterjetWeldingGrinding | ISO 9001 |
| Lee Precision Machine Shop Inc. Milling, Turning, Bending, Welding, EDM · ISO 9001, ITAR | Athens, AL | MillingTurningBendingWeldingEDM | ISO 9001, ITAR |
| Lehi Sheet Metal Turning, Laser, Punching, Bending, Welding, Grinding, Finishing · ISO 9001, AS9100, ITAR | Westborough, MA | TurningLaserPunchingBendingWeldingGrindingFinishing | ISO 9001, AS9100, ITAR |
| Lemmatic Precision LLC Milling, Turning, Finishing · ISO 9001, ITAR | American Fork, UT | MillingTurningFinishing | ISO 9001, ITAR |
| Lewis Precision & CNC Inc Milling, Turning, Bending, Welding, Grinding, Finishing · ISO 9001, AS9100 | Theodore, AL | MillingTurningBendingWeldingGrindingFinishing | ISO 9001, AS9100 |
| Lima Sheet Metal Machine and Mfg., Inc Turning, Bending, Welding, Grinding | Lima, OH | TurningBendingWeldingGrinding | - |
| 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 | - |
| Lodolce Machine Co, Inc Milling, Turning, Laser, Welding, EDM, Assembly · ISO 9001, AS9100 | Saugerties, NY | MillingTurningLaserWeldingEDMAssembly | ISO 9001, AS9100 |
| Logan Machine Co Milling, Turning, Bending, Welding | Akron, OH | MillingTurningBendingWelding | - |
| Loughmiller Machine, Tool & Design Milling, Turning, Waterjet, Welding, EDM, Finishing | Loogootee, IN | MillingTurningWaterjetWeldingEDMFinishing | - |
| Loutech LLC Milling, Turning, Swiss, Finishing · ISO 9001, AS9100, ITAR | Chino, CA | MillingTurningSwissFinishing | ISO 9001, AS9100, ITAR |
| Lovejoy Chaplet Corp Milling, Turning, Swiss | Hoosick Falls, NY | MillingTurningSwiss | - |
| M & S Machining Inc Milling, Turning, Bending, Welding, EDM, Assembly · ISO 9001, AS9100, ITAR | Winchester, KY | MillingTurningBendingWeldingEDMAssembly | ISO 9001, AS9100, ITAR |
| Mac Smith Corp Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, Grinding | Gardena, CA | MillingTurningLaserWaterjetBendingWeldingStampingGrinding | - |
| Mac-Tech Turning, Bending, Laser, Welding | Milwaukee, WI | TurningBendingLaserWelding | - |
| Mach3 Machining Milling, Turning, Welding · ISO 9001 | Cuyahoga Falls, OH | MillingTurningWelding | ISO 9001 |
| Machining Systems Corporation Milling, Turning, Welding, Grinding, Finishing · ISO 9001 | Crestwood, IL | MillingTurningWeldingGrindingFinishing | ISO 9001 |
| 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 | - |
| Magnum Machine Inc Milling, Turning, Welding, Finishing · ITAR | Raymond, NH | MillingTurningWeldingFinishing | ITAR |