| 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 |
| 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 | - |
| Harcon Precision Metals, Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing | San Diego, CA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishing | - |
| Hards Fabrication & Welding, Inc Milling, Turning, Waterjet, Bending, Welding | Seneca, PA | MillingTurningWaterjetBendingWelding | - |
| 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 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 |
| 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 | - |
| Hill Aerosystems Inc Milling, Turning, Waterjet, Punching, Bending, Welding, Stamping, EDM, Assembly · AS9100 | Enumclaw, WA | MillingTurningWaterjetPunchingBendingWeldingStampingEDMAssembly | AS9100 |
| HM Quality Machining Inc Milling, Turning, Laser, Waterjet, Grinding | Ontario, CA | MillingTurningLaserWaterjetGrinding | - |
| Hofacker Precision Machining LLC Milling, Turning, Casting · ISO 9001 | Clayton, OH | MillingTurningCasting | ISO 9001 |
| 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 | - |
| Hood Tooling & Machine LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001 | Malvern, AR | MillingTurningWeldingEDMGrinding | ISO 9001 |
| Horizon Tech Industries Inc Milling, Turning, Swiss, Finishing | Fort Worth, TX | MillingTurningSwissFinishing | - |
| Horst Engineering Milling, Turning · ISO 9001, AS9100 | East Hartford, CT | MillingTurning | ISO 9001, AS9100 |
| Horst Manufacturing Co Inc Milling, Turning | Windham, OH | MillingTurning | - |
| HP Machine & Engineering Inc Milling, Turning, EDM | San Jose, CA | MillingTurningEDM | - |
| HPR Machine Milling, Turning | Vista, CA | MillingTurning | - |
| HR Machine Turning, Waterjet, EDM | Dayton, OH | TurningWaterjetEDM | - |
| Hubbell Machine Co Inc Milling, Turning, Finishing · ISO 9001, AS9100 | Paso Robles, CA | MillingTurningFinishing | ISO 9001, AS9100 |
| Huffman Welding & Machine Inc Milling, Turning, Laser, Waterjet, Bending, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001 | Fort Madison, IA | MillingTurningLaserWaterjetBendingWeldingEDMGrindingFinishingAssembly | ISO 9001 |
| Hunt Enterprises Milling, Turning, Welding | Santa Ana, CA | MillingTurningWelding | - |
| Hyperformance Products Inc Milling, Turning, Punching, Bending, Welding | Huntington Beach, CA | MillingTurningPunchingBendingWelding | - |
| Icc Machining, LLC Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001 | Alvin, TX | MillingTurningWeldingEDMGrindingAssembly | ISO 9001 |
| Idp TM Inc Milling, Turning, EDM · ISO 9001 | Rockwall, TX | MillingTurningEDM | ISO 9001 |
| Impact Machine LLC Milling, Turning · ISO 9001 | Kaukauna, WI | MillingTurning | ISO 9001 |
| Imperial Carbide Inc Milling, Turning, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001 | Meadville, PA | MillingTurningWeldingStampingEDMGrindingFinishing | ISO 9001 |
| 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 |
| Infinisys Manufacturing LLC Milling, Turning, EDM | Phoenix, AZ | MillingTurningEDM | - |