| Hartmann's, Inc Milling, Turning, Welding, Forging, EDM, Grinding, Finishing, Assembly · ISO 9001, ITAR | Abilene, TX | MillingTurningWeldingForgingEDMGrindingFinishingAssembly | ISO 9001, ITAR |
| Hasten Applied CNC LLC Milling, Turning, Swiss, Laser, Bending, Welding, Stamping, EDM, Finishing · ISO 9001, ITAR | Riverside, CA | MillingTurningSwissLaserBendingWeldingStampingEDMFinishing | ISO 9001, ITAR |
| Hastreiter Industries Corp Milling, Turning, Laser, Bending, Welding, Grinding, Finishing · ISO 9001, ITAR | Marshfield, WI | MillingTurningLaserBendingWeldingGrindingFinishing | ISO 9001, ITAR |
| Heighten America, Inc Milling, Turning, Welding, Assembly · ISO 9001 | Oakdale, CA | MillingTurningWeldingAssembly | ISO 9001 |
| Heiton Manufacturing LLC Milling, Turning, Laser, Welding | Forney, TX | MillingTurningLaserWelding | - |
| Henderson Machine, Inc Milling, Turning, Swiss, Welding, EDM · ITAR | Deerfield Beach, FL | MillingTurningSwissWeldingEDM | ITAR |
| Henry's Metal Polishing, Inc Turning, Bending, Welding, Grinding, Finishing · ISO 9001 | S El Monte, CA | TurningBendingWeldingGrindingFinishing | ISO 9001 |
| Heritage Fabrication Inc Milling, Turning, Laser, Punching, Bending, Welding, Finishing | Sedalia, MO | MillingTurningLaserPunchingBendingWeldingFinishing | - |
| Herker Industries Inc Milling, Turning, Swiss, Welding, Assembly · ISO 9001 | Menomonee Falls, WI | MillingTurningSwissWeldingAssembly | ISO 9001 |
| High Star Corp Milling, Turning, Bending, Welding, Stamping, Grinding, Finishing · ISO 9001 | Westland, MI | MillingTurningBendingWeldingStampingGrindingFinishing | ISO 9001 |
| High Tech Machine II Co Limited Milling, Turning, Welding, EDM | Houston, TX | MillingTurningWeldingEDM | - |
| Hill Aerosystems Inc Milling, Turning, Waterjet, Punching, Bending, Welding, Stamping, EDM, Assembly · AS9100 | Enumclaw, WA | MillingTurningWaterjetPunchingBendingWeldingStampingEDMAssembly | AS9100 |
| Hillco Contracting LLC Milling, Turning, Welding, Grinding | Bates City, MO | MillingTurningWeldingGrinding | - |
| Hilton Tool Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100 | Clackamas, OR | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100 |
| Hogin Machine, Inc Milling, Turning, Swiss, Waterjet, Bending, Welding | Santa Ana, CA | MillingTurningSwissWaterjetBendingWelding | - |
| Holden on Motorsports, LLC Turning, Laser, Welding, Grinding | Zephyrhills, FL | TurningLaserWeldingGrinding | - |
| HollyFab Turning, Bending, Laser, Welding, Waterjet | Addison, TX | TurningBendingLaserWeldingWaterjet | - |
| Holzman Machine LLC Milling, Turning, Welding · ITAR | Clearwater, FL | MillingTurningWelding | ITAR |
| Hood Tooling & Machine LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001 | Malvern, AR | MillingTurningWeldingEDMGrinding | ISO 9001 |
| Hughes Machine Shop, Inc Milling, Turning, Waterjet, Welding · ISO 9001 | Bogalusa, LA | MillingTurningWaterjetWelding | ISO 9001 |
| Hunt Enterprises Milling, Turning, Welding | Santa Ana, CA | MillingTurningWelding | - |
| I Auman Machine Co Inc Milling, Turning, Welding | Lebanon, PA | MillingTurningWelding | - |
| I.p. Automation, Inc Milling, Turning, Laser, Waterjet, Bending, Welding, Grinding · ISO 9001 | Colorado Springs, CO | MillingTurningLaserWaterjetBendingWeldingGrinding | ISO 9001 |
| Imperial Carbide Inc Milling, Turning, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001 | Meadville, PA | MillingTurningWeldingStampingEDMGrindingFinishing | ISO 9001 |
| Independent Machine Company Milling, Turning, Laser, Welding, Grinding | Escanaba, MI | MillingTurningLaserWeldingGrinding | - |
| Indus Precision Mfg., Inc Milling, Turning, Waterjet, Bending, Welding, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, CMMC | Congers, NY | MillingTurningWaterjetBendingWeldingGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Industrial Chrome Inc Milling, Turning, Laser, Bending, Welding, Grinding, Finishing, Assembly · ISO 9001 | Topeka, KS | MillingTurningLaserBendingWeldingGrindingFinishingAssembly | ISO 9001 |
| Industrial Fabricators Milling, Turning, Bending, Welding, Waterjet | Corpus Christi, TX | MillingTurningBendingWeldingWaterjet | - |
| Industrial Motions Engineering, Inc Milling, Turning, Welding, Grinding, Finishing, Assembly | Wilmington, MA | MillingTurningWeldingGrindingFinishingAssembly | - |
| Industrial Screen & Maintenance, Inc Milling, Turning, Welding, Casting, Grinding · ISO 9001 | Casper, WY | MillingTurningWeldingCastingGrinding | ISO 9001 |
| Inland Marine Industries Inc Milling, Turning, Waterjet, Punching, Bending, Welding, Grinding, Finishing · ISO 9001, ITAR | Hayward, CA | MillingTurningWaterjetPunchingBendingWeldingGrindingFinishing | ISO 9001, ITAR |
| Innovated Metal Fabrication, Inc Turning, Bending, Laser, Welding | Maplewood, MN | TurningBendingLaserWelding | - |
| Innovation Alley Milling, Turning, Bending, Welding | Fresno, CA | MillingTurningBendingWelding | - |
| InSight Manufacturing Milling, Turning, Welding, Forging, Assembly | Murphys, CA | MillingTurningWeldingForgingAssembly | - |
| Integra Cast Milling, Turning, Welding, Casting, Finishing, Assembly · ISO 9001, NADCAP | New Britain, CT | MillingTurningWeldingCastingFinishingAssembly | ISO 9001, NADCAP |
| Integrated Machining Co Milling, Turning, Welding, EDM, Grinding · ISO 9001, ITAR | Albuquerque, NM | MillingTurningWeldingEDMGrinding | ISO 9001, ITAR |
| Interactive Manufacturing, Inc Milling, Turning, Waterjet, Welding, Finishing, Assembly | Central Point, OR | MillingTurningWaterjetWeldingFinishingAssembly | - |
| International Precision Manufacturing LLC Milling, Turning, Welding, EDM, Assembly · ISO 9001, AS9100, ISO 13485 | Houston, TX | MillingTurningWeldingEDMAssembly | ISO 9001, AS9100, ISO 13485 |
| Iowa Metal Spinners Milling, Turning, Laser, Welding, Stamping · ISO 9001 | Cedar Falls, IA | MillingTurningLaserWeldingStamping | ISO 9001 |
| IPMI Manufacturing & Engineering Milling, Turning, Welding | Buckner, MO | MillingTurningWelding | - |
| Irwin Automation Inc Milling, Turning, Welding, EDM, Grinding | Greensburg, PA | MillingTurningWeldingEDMGrinding | - |
| 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 B Tool Die & Engineering Co Inc Milling, Turning, Welding, Stamping, EDM, Grinding · ISO 9001 | Fort Wayne, IN | MillingTurningWeldingStampingEDMGrinding | ISO 9001 |
| J.B. Anderson & Son, Inc Milling, Turning, Welding, Assembly | Irwin, PA | MillingTurningWeldingAssembly | - |
| J&M Machining Milling, Turning, Welding, Casting, Finishing · ISO 9001 | Norton Shores, MI | MillingTurningWeldingCastingFinishing | ISO 9001 |
| Jacksonville Machine, Inc Milling, Turning, Welding, Grinding · ISO 9001 | Jacksonville, IL | MillingTurningWeldingGrinding | ISO 9001 |
| Jaffa Precision Engineering Inc Milling, Turning, Swiss, Welding, Grinding, Finishing · ISO 9001 | Riverside, CA | MillingTurningSwissWeldingGrindingFinishing | ISO 9001 |
| JBC Machine Inc Milling, Turning, Welding, Finishing | Hortonville, WI | MillingTurningWeldingFinishing | - |
| JC Custom Machining & Design Inc Milling, Turning, Welding, Grinding | Hillsboro, OR | MillingTurningWeldingGrinding | - |