| Gtscientific LLC Milling, Turning, Laser, Welding, Grinding | Honolulu, HI | MillingTurningLaserWeldingGrinding | - |
| Gurecky Manufacturing Service, Inc Milling, Turning, Welding, EDM, Assembly · ISO 9001 | Rosenberg, TX | MillingTurningWeldingEDMAssembly | ISO 9001 |
| H & H Machine Shop of Akron Inc Milling, Turning, Welding, Grinding | Akron, OH | MillingTurningWeldingGrinding | - |
| H & S Tool and Engineering, Inc Milling, Turning, Welding, EDM · ISO 9001 | Fall River, MA | MillingTurningWeldingEDM | ISO 9001 |
| H&H Metal Fabrication Bending, Welding | St. Louis, MO | BendingWelding | - |
| H&S Manufacturing Co Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100, ITAR | Rowlett, TX | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100, ITAR |
| H3 Manufacturing Group LLC Laser, Bending, Welding, Finishing · ISO 9001 | Schaumburg, IL | LaserBendingWeldingFinishing | ISO 9001 |
| Hagan Design & Machine Inc Milling, Turning, Welding, EDM, Grinding | Newmarket, NH | MillingTurningWeldingEDMGrinding | - |
| Haig Precision Manufacturing Corp Milling, Turning, Laser, Punching, Bending, Welding, Stamping, EDM, Grinding, Finishing, Assembly | San Jose, CA | MillingTurningLaserPunchingBendingWeldingStampingEDMGrindingFinishingAssembly | - |
| 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 |
| Halsey MFG Milling, Turning, Laser, Welding, Metal AM | Denton, TX | MillingTurningLaserWeldingMetal AM | - |
| 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 | - |
| Hammer MetalWerks Bending, Laser, Welding | Indianapolis, IN | BendingLaserWelding | - |
| Hammond Machine Works, Inc Laser, Welding, Grinding, Assembly | Hammond, IN | LaserWeldingGrindingAssembly | - |
| Hampton Sheet Metal Inc Bending, Welding | Newport News, VA | BendingWelding | - |
| Hanset Stainless Inc Welding | Portland, OR | Welding | - |
| Harbor Fab Welding | Fort Worth, TX | Welding | - |
| Harcon Precision Metals, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing | San Diego, CA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishing | - |
| Hard Chrome Specialists, Inc Bending, Welding, Grinding, Finishing · ISO 9001 | York, PA | BendingWeldingGrindingFinishing | ISO 9001 |
| Hardcraft Industries Inc Laser, Bending, Welding, Assembly · ISO 9001 | San Jose, CA | LaserBendingWeldingAssembly | ISO 9001 |
| Harris Machine Co Milling, Bending, Welding, Finishing, Assembly | Oakes, ND | MillingBendingWeldingFinishingAssembly | - |
| Harshco, L.L.C Milling, Turning, Swiss, Laser, Waterjet, Bending, Welding · ISO 9001, AS9100 | Scottsdale, AZ | MillingTurningSwissLaserWaterjetBendingWelding | ISO 9001, AS9100 |
| Hart Industries LLC Waterjet, Bending, Welding, Grinding, Finishing, Assembly | Sterling Heights, MI | WaterjetBendingWeldingGrindingFinishingAssembly | - |
| 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 | - |
| 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 |
| Hayes Manufacturing Company, Incorporated Milling, Welding | Pineville, LA | MillingWelding | - |
| Heavy Metal Laser Laser, Bending, Welding, Finishing | Ogden, UT | LaserBendingWeldingFinishing | - |
| Heighten America, Inc Milling, Turning, Welding, Assembly · ISO 9001 | Oakdale, CA | MillingTurningWeldingAssembly | ISO 9001 |
| Heimaster Metal Works Inc Bending, Welding | Lakeside, CA | BendingWelding | - |
| 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 |
| Herold Precision Metals, LLC Milling, Laser, Punching, Bending, Welding, Stamping, Finishing, Assembly · ISO 9001, ITAR | White Bear Lake, MN | MillingLaserPunchingBendingWeldingStampingFinishingAssembly | ISO 9001, ITAR |
| HG Metals Bending, Welding | Indianapolis, IN | BendingWelding | - |
| 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 | - |
| 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 |
| 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 |
| HMF Corporation Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| Hobart Machined Products Inc Welding, Assembly | Maple Valley, WA | WeldingAssembly | - |
| Hogin Machine, Inc Milling, Turning, Swiss, Waterjet, Bending, Welding | Santa Ana, CA | MillingTurningSwissWaterjetBendingWelding | - |
| Holbrook Laser, Welding | Franklin, IN | LaserWelding | - |