| I.p. Automation, Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Grinding · ISO 9001 | Colorado Springs, CO | MillingTurningLaserWaterjetBendingWeldingGrinding | ISO 9001 |
| Ica Corp Milling, Laser, Assembly · ISO 9001, ITAR | Maple Grove, MN | MillingLaserAssembly | ISO 9001, ITAR |
| Ifl Manufacturing Inc Milling, Stamping | Wauconda, IL | MillingStamping | - |
| Independent Machine Company Milling, Turning, Laser, Welding, Grinding | Escanaba, MI | MillingTurningLaserWeldingGrinding | - |
| Independent Sheet Metal LLC Punching, Welding | Middletown, OH | PunchingWelding | - |
| Industrial Experimental Technologies, LLC Welding, Stamping · ISO 9001 | Auburn Hills, MI | WeldingStamping | ISO 9001 |
| 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 | - |
| Insulfab Plastics Inc Stamping, EDM · ITAR | Franklin, NH | StampingEDM | ITAR |
| Integrated Ideas & Technologies Inc Laser, Waterjet, Bending | Coeur D Alene, ID | LaserWaterjetBending | - |
| Inter-Precision Mold Inc Milling, Turning, Welding, EDM, Grinding, Assembly | El Paso, TX | MillingTurningWeldingEDMGrindingAssembly | - |
| Interstate Manufacturing Company, Inc Milling, Welding · ITAR | Agawam, MA | MillingWelding | ITAR |
| IntoMetal Bending, Laser, Welding, Metal AM | Lincoln, NE | BendingLaserWeldingMetal AM | - |
| Iowa Metal Spinners Milling, Turning, Laser, Welding, Stamping · ISO 9001 | Cedar Falls, IA | MillingTurningLaserWeldingStamping | ISO 9001 |
| Ironleaf Designs, LLC Laser | Pineville, NC | Laser | - |
| ISCO Manufacturing Solutions Milling, Turning, Waterjet, Bending, Welding, Grinding · ISO 9001, AS9100 | Bend, OR | MillingTurningWaterjetBendingWeldingGrinding | ISO 9001, AS9100 |
| J & A Manufacturing, Inc Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Garland, TX | LaserPunchingBendingWeldingFinishingAssembly | ISO 9001 |
| J & N Metal Products, LLC Milling, Laser, Bending, Welding, EDM · ISO 9001 | Brazil, IN | MillingLaserBendingWeldingEDM | ISO 9001 |
| 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 Newell Corp Milling, Welding | Arlington, WA | MillingWelding | - |
| J W Machine & Fab LLC Milling, Turning, Welding, Grinding | Fountain Inn, SC | MillingTurningWeldingGrinding | - |
| J. T. Cullen Co Inc Milling | Fulton, IL | Milling | - |
| J.i.t. Manufacturing, Inc Milling, Laser, Punching, Bending, Welding, Finishing, Assembly | Cowpens, SC | MillingLaserPunchingBendingWeldingFinishingAssembly | - |
| Jax Fab Shop LLC Welding | Jacksonville, FL | Welding | - |
| Jax Laser Solutions LLC Laser | Jacksonville, FL | Laser | - |
| JC Macelroy Co Inc Milling, Punching, Bending, Welding, Grinding, Assembly | Piscataway, NJ | MillingPunchingBendingWeldingGrindingAssembly | - |
| JC Machine, Inc Milling, Turning, Swiss, Laser, Bending, Welding | Lakeland, FL | MillingTurningSwissLaserBendingWelding | - |
| JD Laser Inc Laser, Bending | Hartford, WI | LaserBending | - |
| 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 |
| Jet Speed Metals Bending, Welding | Westbrook, ME | BendingWelding | - |
| Jetfab LLC Milling, Turning, Laser, Waterjet, Punching, Bending, Welding | Lowell, MA | MillingTurningLaserWaterjetPunchingBendingWelding | - |
| Jkeys LLC Laser, Bending, Finishing | Willis, TX | LaserBendingFinishing | - |
| John W. McDougall Co. Bending, Laser, Welding · ISO 9001 | Nashville, TN | BendingLaserWelding | ISO 9001 |
| Jones Co Machining Milling, Turning, Welding, Assembly | Hannibal, MO | MillingTurningWeldingAssembly | - |
| Jones Metal, Inc Milling, Laser, Waterjet, Bending, Welding, Finishing, Assembly | Mankato, MN | MillingLaserWaterjetBendingWeldingFinishingAssembly | - |
| Just One More Part, LLC Bending, Welding, Finishing | Pottstown, PA | BendingWeldingFinishing | - |
| Justified Performance LLC Laser, Bending, Welding, Finishing, Assembly · ISO 9001 | Rocklin, CA | LaserBendingWeldingFinishingAssembly | ISO 9001 |
| K&B Industries Turning, Assembly · ISO 9001 | Houma, LA | TurningAssembly | ISO 9001 |
| Kammerer Dynamics Inc Laser, Bending, Welding, Casting, Finishing, Assembly | Kendallville, IN | LaserBendingWeldingCastingFinishingAssembly | - |
| Kaskaskia Tool and Machine, Inc Milling, Turning, Bending, Welding, Stamping, EDM, Grinding · ISO 9001, AS9100 | New Athens, IL | MillingTurningBendingWeldingStampingEDMGrinding | ISO 9001, AS9100 |
| KBM Industries Bending, Welding | Mechanicsburg, PA | BendingWelding | - |
| Kencoa Aerospace LLC Milling, Turning, Waterjet, Punching, Bending, Welding, Stamping · AS9100, ITAR | Eastman, GA | MillingTurningWaterjetPunchingBendingWeldingStamping | AS9100, ITAR |
| Kenney Industries, Inc. Bending, Welding · ISO 9001, NADCAP | Dallas, TX | BendingWelding | ISO 9001, NADCAP |
| 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 | - |