| Hansens Welding Inc Waterjet, Welding | Gardena, CA | WaterjetWelding | - |
| Hards Fabrication & Welding, Inc Milling, Turning, Waterjet, Bending, Welding | Seneca, PA | MillingTurningWaterjetBendingWelding | - |
| Hartman Enterprises Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, AS9100, ITAR | Oneida, NY | MillingTurningSwissGrindingFinishing | ISO 9001, AS9100, ITAR |
| Hasten Applied CNC LLC Milling, Turning, Swiss, Laser, Bending, Welding, Stamping, EDM, Finishing · ISO 9001, ITAR | Riverside, CA | MillingTurningSwissLaserBendingWeldingStampingEDMFinishing | ISO 9001, ITAR |
| Hi Tech Machining & Engineering LLC Milling, Turning, EDM, Grinding | Tucson, AZ | MillingTurningEDMGrinding | - |
| High Speed CNC Milling, Turning · ISO 9001, AS9100 | Santa Clara, CA | MillingTurning | ISO 9001, AS9100 |
| Hill Aerosystems Inc Milling, Turning, Waterjet, Punching, Bending, Welding, Stamping, EDM, Assembly · AS9100 | Enumclaw, WA | MillingTurningWaterjetPunchingBendingWeldingStampingEDMAssembly | AS9100 |
| Hirsh Precision Products, Inc Milling, Turning, Assembly · AS9100, ITAR, ISO 13485 | Frederick, CO | MillingTurningAssembly | AS9100, ITAR, ISO 13485 |
| Hofacker Precision Machining LLC Milling, Turning, Casting · ISO 9001 | Clayton, OH | MillingTurningCasting | ISO 9001 |
| Hogin Machine, Inc Milling, Turning, Swiss, Waterjet, Bending, Welding | Santa Ana, CA | MillingTurningSwissWaterjetBendingWelding | - |
| Hood Tooling & Machine LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001 | Malvern, AR | MillingTurningWeldingEDMGrinding | ISO 9001 |
| Horst Engineering Milling, Turning · ISO 9001, AS9100 | East Hartford, CT | MillingTurning | ISO 9001, AS9100 |
| Hunt Design & Manufacturing Inc Milling, Turning, Swiss, EDM, Grinding · AS9100 | Arab, AL | MillingTurningSwissEDMGrinding | AS9100 |
| Hydrafab Northwest, Inc Laser, Bending, Welding | Spokane Valley, WA | LaserBendingWelding | - |
| Ideal Technology Corp Milling, Turning, Welding, Casting, Metal AM, Grinding · ISO 9001 | Shelby Township, MI | MillingTurningWeldingCastingMetal AMGrinding | ISO 9001 |
| IFT Worldwide Milling, Stamping, Finishing | South Bend, IN | MillingStampingFinishing | - |
| Impulse Precision Manufacturing Milling, Stamping, Finishing · ISO 9001, ITAR, NADCAP | Wilsonville, OR | MillingStampingFinishing | ISO 9001, ITAR, NADCAP |
| In Tolerance Contract Manufacturing Milling, Turning, Bending · ISO 9001, AS9100, NADCAP | Cedar Rapids, IA | MillingTurningBending | ISO 9001, AS9100, NADCAP |
| Industrial Experimental Technologies, LLC Welding, Stamping · ISO 9001 | Auburn Hills, MI | WeldingStamping | ISO 9001 |
| Industrial Fabricators Milling, Turning, Bending, Welding, Waterjet | Corpus Christi, TX | MillingTurningBendingWeldingWaterjet | - |
| Industrial Manufacturing Specialties, Inc Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100 | Decatur, AL | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100 |
| Infiniti Manufacture Milling, Welding, Finishing | Corona, CA | MillingWeldingFinishing | - |
| Infinity Precision Inc Milling, Turning, Waterjet, Bending, Grinding · ISO 9001, AS9100 | Simi Valley, CA | MillingTurningWaterjetBendingGrinding | ISO 9001, AS9100 |
| Infinity Precision Machining LLC Milling, Turning | Buffalo, NY | MillingTurning | - |
| Integra Cast Milling, Turning, Welding, Casting, Finishing, Assembly · ISO 9001, NADCAP | New Britain, CT | MillingTurningWeldingCastingFinishingAssembly | ISO 9001, NADCAP |
| Interlake Stamping of Ohio Inc Stamping, Assembly | Willoughby, OH | StampingAssembly | - |
| Inventery Precision Milling, Turning, Swiss, Finishing, Assembly · ISO 9001, AS9100, ITAR, CMMC | Pasadena, CA | MillingTurningSwissFinishingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Ipanel Systems Inc Milling | Santa Clarita, CA | Milling | - |
| Iridium Manufacturing Milling, Turning, Waterjet, EDM, Grinding · ISO 9001 | Washington, MI | MillingTurningWaterjetEDMGrinding | ISO 9001 |
| ISCO Manufacturing Solutions Milling, Turning, Waterjet, Bending, Welding, Grinding · ISO 9001, AS9100 | Bend, OR | MillingTurningWaterjetBendingWeldingGrinding | ISO 9001, AS9100 |
| Ital-Tech Machined Products, LLC Milling, Turning, Welding, Grinding · ISO 9001, ITAR | Groveland, MA | MillingTurningWeldingGrinding | ISO 9001, ITAR |
| J & L Precision Manufacturing LLC Bending, Welding, Stamping, Finishing, Assembly · ISO 9001 | Brooklyn Heights, OH | BendingWeldingStampingFinishingAssembly | ISO 9001 |
| J & N Metal Products, LLC Milling, Laser, Bending, Welding, EDM · ISO 9001 | Brazil, IN | MillingLaserBendingWeldingEDM | ISO 9001 |
| J A-Co Machine Works, LLC Milling, Turning, Swiss, Welding, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 | Scotts Valley, CA | MillingTurningSwissWeldingFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP, ISO 13485 |
| J Newell Corp Milling, Welding | Arlington, WA | MillingWelding | - |
| J'evac Machine, Inc Milling, Turning, Swiss, Waterjet, Bending, Welding, Finishing · ISO 9001, AS9100, NADCAP | Magnolia, AR | MillingTurningSwissWaterjetBendingWeldingFinishing | ISO 9001, AS9100, NADCAP |
| Jaco Engineering Milling, Turning, Bending, Welding, EDM, Grinding, Finishing, Assembly · NADCAP | Anaheim, CA | MillingTurningBendingWeldingEDMGrindingFinishingAssembly | NADCAP |
| James Tool Machine & Engineering Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, AS9100 | Morganton, NC | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, AS9100 |
| Jarvis Manufacturing, Inc Milling, Turning, EDM, Assembly · ISO 9001, ITAR | San Jose, CA | MillingTurningEDMAssembly | ISO 9001, ITAR |
| JB Precision Machining, Inc Milling, Turning | Brentwood, NY | MillingTurning | - |
| JBC Machine Inc Milling, Turning, Welding, Finishing | Hortonville, WI | MillingTurningWeldingFinishing | - |
| JCB Precision, LLC Milling | Concord, NH | Milling | - |
| JD Machine Milling, Turning, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningBendingWeldingEDM | ISO 9001, AS9100, ITAR, CMMC |
| Jep Manufacturing LLC Milling, Turning, Welding · ISO 9001 | Rosenberg, TX | MillingTurningWelding | ISO 9001 |
| Jerl Machine Inc Milling, Turning, Welding, Casting, EDM, Grinding, Assembly · ISO 9001 | Perrysburg, OH | MillingTurningWeldingCastingEDMGrindingAssembly | ISO 9001 |
| Jet Machined Products, LLC Milling, Turning, Stamping, Grinding · ISO 9001, ITAR | East Bridgewater, MA | MillingTurningStampingGrinding | ISO 9001, ITAR |
| JJR Engineering & Fabrication Inc Milling, Turning, Bending, Welding, Stamping, Finishing, Assembly · ISO 9001, AS9100, NADCAP | Woodinville, WA | MillingTurningBendingWeldingStampingFinishingAssembly | ISO 9001, AS9100, NADCAP |
| JMR Machining LLC Milling, Turning, Casting, Finishing | Athens, TX | MillingTurningCastingFinishing | - |
| John J Steuby Co Milling, Turning, Swiss, Welding, Stamping, Casting, EDM, Finishing · ISO 9001, ITAR | Hazelwood, MO | MillingTurningSwissWeldingStampingCastingEDMFinishing | ISO 9001, ITAR |
| Johnson Manufacturing Systems LLC Milling, Turning, Welding, Grinding | Miamisburg, OH | MillingTurningWeldingGrinding | - |