| Halcyon Manufacturing Inc Milling, Turning, Bending, Welding, EDM, Finishing, Assembly · ITAR | San Jose, CA | MillingTurningBendingWeldingEDMFinishingAssembly | ITAR |
| Halfab, Inc Milling, Turning, Welding, Finishing | Livermore, CA | MillingTurningWeldingFinishing | - |
| Hallmark Metals Inc Milling, Turning, Laser, Punching, Welding, Stamping, Finishing · ISO 9001, ITAR, NADCAP | Glendora, CA | MillingTurningLaserPunchingWeldingStampingFinishing | ISO 9001, ITAR, NADCAP |
| Hallnus Works Milling, Finishing · ISO 9001, ITAR | Battle Ground, WA | MillingFinishing | ISO 9001, ITAR |
| Halo Metal Prep Inc Stamping, Finishing · ISO 9001 | Cleveland, OH | StampingFinishing | ISO 9001 |
| Hamblen Machine Inc Milling, Turning, EDM, Grinding | Bloomington, IN | MillingTurningEDMGrinding | - |
| Hamill Manufacturing Co Milling, Turning, Welding, EDM · ISO 9001, ITAR | Trafford, PA | MillingTurningWeldingEDM | ISO 9001, ITAR |
| Hamilton Machine Co. Milling, Turning, Bending, Welding | Nashville, TN | MillingTurningBendingWelding | - |
| Hampton Sheet Metal Inc Bending, Welding | Newport News, VA | BendingWelding | - |
| Haney Manufacturing LLC Milling | Kingston, TN | Milling | - |
| Hanset Stainless Inc Welding | Portland, OR | Welding | - |
| Harbor Island Supply Corporation Casting | Seattle, WA | Casting | - |
| Harcon Precision Metals, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing | San Diego, CA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishing | - |
| Hardric Laboratories, Inc Milling, EDM · ISO 9001 | Hudson, NH | MillingEDM | ISO 9001 |
| Hards Fabrication & Welding, Inc Milling, Turning, Waterjet, Bending, Welding | Seneca, PA | MillingTurningWaterjetBendingWelding | - |
| Harrison Electropolishing, L.P Welding, Finishing · ISO 9001 | Houston, TX | WeldingFinishing | ISO 9001 |
| Harshco, L.L.C Milling, Turning, Swiss, Laser, Waterjet, Bending, Welding · ISO 9001, AS9100 | Scottsdale, AZ | MillingTurningSwissLaserWaterjetBendingWelding | ISO 9001, AS9100 |
| Hartman Enterprises Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, AS9100, ITAR | Oneida, NY | MillingTurningSwissGrindingFinishing | ISO 9001, AS9100, ITAR |
| Hartmann's, Inc Milling, Turning, Welding, Forging, EDM, Grinding, Finishing, Assembly · ISO 9001, ITAR | Abilene, TX | MillingTurningWeldingForgingEDMGrindingFinishingAssembly | ISO 9001, ITAR |
| Harvey Brothers Inc Bending, Welding | Cincinnati, OH | BendingWelding | - |
| Harvey Vogel Manufacturing Co Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Saint Paul, MN | MillingTurningLaserWaterjetPunchingBendingWeldingStampingEDMGrindingFinishingAssembly | ISO 9001, AS9100 |
| 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 |
| Hawkins Machine Co Inc Milling, Welding, Grinding | Coventry, RI | MillingWeldingGrinding | - |
| Hayes Manufacturing Company, Incorporated Milling, Welding | Pineville, LA | MillingWelding | - |
| Heavy Metal Laser Laser, Bending, Welding, Finishing | Ogden, UT | LaserBendingWeldingFinishing | - |
| Helander Metal Spinning Company LLC Milling, Turning, Laser, Waterjet, Welding, Stamping, EDM, Finishing · NADCAP | Lombard, IL | MillingTurningLaserWaterjetWeldingStampingEDMFinishing | NADCAP |
| Helical Machining, Inc Milling, Turning, Welding, EDM, Grinding, Finishing, Assembly | Sun Valley, CA | MillingTurningWeldingEDMGrindingFinishingAssembly | - |
| 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 | - |
| Heyel Custom Metal Milling, Turning, Bending, Laser, Welding, Waterjet | Raleigh, NC | MillingTurningBendingLaserWeldingWaterjet | - |
| Hi Performance Machine & Metals, Inc Milling, Turning, Waterjet, EDM · ISO 9001 | Lakeside, CA | MillingTurningWaterjetEDM | ISO 9001 |
| High Speed CNC Milling, Turning · ISO 9001, AS9100 | Santa Clara, CA | MillingTurning | ISO 9001, AS9100 |
| High Tech Machine II Co Limited Milling, Turning, Welding, EDM | Houston, TX | MillingTurningWeldingEDM | - |
| Highway Machine Co Inc Milling, Welding, Grinding | Princeton, IN | MillingWeldingGrinding | - |
| Hill Aerosystems Inc Milling, Turning, Waterjet, Punching, Bending, Welding, Stamping, EDM, Assembly · AS9100 | Enumclaw, WA | MillingTurningWaterjetPunchingBendingWeldingStampingEDMAssembly | AS9100 |
| Hilltop Technology Laboratory Inc Milling | Irvine, CA | Milling | - |
| HK Manufacturing Services LLC Milling | Everett, WA | Milling | - |
| HM Quality Machining Inc Milling, Turning, Laser, Waterjet, Grinding | Ontario, CA | MillingTurningLaserWaterjetGrinding | - |
| HMF Corporation Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| HNDO Precision Milling, Laser, Finishing | Santa Rosa, CA | MillingLaserFinishing | - |
| Hobart Machined Products Inc Welding, Assembly | Maple Valley, WA | WeldingAssembly | - |
| Hofacker Precision Machining LLC Milling, Turning, Casting · ISO 9001 | Clayton, OH | MillingTurningCasting | ISO 9001 |
| Holbrook Laser, Welding | Franklin, IN | LaserWelding | - |
| Holden on Motorsports, LLC Turning, Laser, Welding, Grinding | Zephyrhills, FL | TurningLaserWeldingGrinding | - |
| HollyFab Turning, Bending, Laser, Welding, Waterjet | Addison, TX | TurningBendingLaserWeldingWaterjet | - |
| Holz Enterprises, Inc Milling, Turning, Finishing · AS9100, ITAR | Bellingham, WA | MillingTurningFinishing | AS9100, ITAR |
| Holzman Machine LLC Milling, Turning, Welding · ITAR | Clearwater, FL | MillingTurningWelding | ITAR |
| Homebase Machining LLC Milling, Turning | Meridian, ID | MillingTurning | - |