| H & W Machine Repair & Rebuilding Milling, Turning, Welding | Fort Wayne, IN | MillingTurningWelding | - |
| Hadley Precision Milling, Turning, Welding | Baton Rouge, LA | MillingTurningWelding | - |
| Halsey MFG Milling, Turning, Laser, Welding, Metal AM | Denton, TX | MillingTurningLaserWeldingMetal AM | - |
| Hamilton Machine Co. Milling, Turning, Bending, Welding | Nashville, TN | MillingTurningBendingWelding | - |
| Hart Precision Machining Milling, Turning, EDM · ISO 9001, AS9100 | Redford Township, MI | MillingTurningEDM | ISO 9001, AS9100 |
| Heyel Custom Metal Milling, Turning, Bending, Laser, Welding, Waterjet | Raleigh, NC | MillingTurningBendingLaserWeldingWaterjet | - |
| High Performance Engineering Milling, Turning, Bending, EDM | Sioux Falls, SD | MillingTurningBendingEDM | - |
| High Speed CNC Milling, Turning · ISO 9001, AS9100 | Santa Clara, CA | MillingTurning | ISO 9001, AS9100 |
| Horst Engineering Milling, Turning · ISO 9001, AS9100 | East Hartford, CT | MillingTurning | ISO 9001, AS9100 |
| HR CNC Milling | Clearwater, FL | Milling | - |
| Icon Machine Co Milling, Turning, Casting · ISO 9001, AS9100 | Irving, TX | MillingTurningCasting | ISO 9001, AS9100 |
| Imagineering Machine Inc Milling, Turning, Casting · NADCAP | St Louis Park, MN | MillingTurningCasting | NADCAP |
| In Tolerance Contract Manufacturing Milling, Turning, Bending · ISO 9001, AS9100, NADCAP | Cedar Rapids, IA | MillingTurningBending | ISO 9001, AS9100, NADCAP |
| Incremental Machine Milling, Bending | Baltimore, MD | MillingBending | - |
| Industrial Fabricators Milling, Turning, Bending, Welding, Waterjet | Corpus Christi, TX | MillingTurningBendingWeldingWaterjet | - |
| Industrial Sales & Manufacturing, Inc. Milling, Turning, Bending, Laser, Welding · ISO 9001 | Erie, PA | MillingTurningBendingLaserWelding | ISO 9001 |
| Infinity Precision Machining LLC Milling, Turning | Buffalo, NY | MillingTurning | - |
| Inno Tech Manufacturing Inc Milling, Turning, Laser · AS9100 | San Diego, CA | MillingTurningLaser | AS9100 |
| Innovation Alley Milling, Turning, Bending, Welding | Fresno, CA | MillingTurningBendingWelding | - |
| IPMI Manufacturing & Engineering Milling, Turning, Welding | Buckner, MO | MillingTurningWelding | - |
| IronStrong Metal Fabrication LLC Milling, Bending, Laser, Welding | Lancaster, PA | MillingBendingLaserWelding | - |
| J&J Machine Milling, EDM | Appleton, WI | MillingEDM | - |
| Jaguar Precision Machine, LLC. Milling, Turning, Bending, Welding, Waterjet, Stamping, Metal AM · ISO 9001, AS9100, ITAR | Albuquerque, NM | MillingTurningBendingWeldingWaterjetStampingMetal AM | ISO 9001, AS9100, ITAR |
| Jax Precision Milling, Turning, Bending, Metal AM · ISO 9001, AS9100, ITAR | Jacksonville, FL | MillingTurningBendingMetal AM | ISO 9001, AS9100, ITAR |
| JD Machine Milling, Turning, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningBendingWeldingEDM | ISO 9001, AS9100, ITAR, CMMC |
| Jewett Machine Milling, Turning, Welding · ISO 9001 | Richmond, VA | MillingTurningWelding | ISO 9001 |
| JP Metal Fabrication, Inc. Milling, Bending, Laser, Welding | Santa Clara, CA | MillingBendingLaserWelding | - |
| Just In Time Machine Corp Milling, Turning, Welding · AS9100, ITAR | Middleton, WI | MillingTurningWelding | AS9100, ITAR |
| JW Machine (Praesto Enterprises, LLC) Milling, Turning, Laser · ISO 9001, AS9100, ITAR | Orlando, FL | MillingTurningLaser | ISO 9001, AS9100, ITAR |
| K C Machine Milling, Turning, Waterjet · ISO 9001, AS9100 | Excelsior Springs, MO | MillingTurningWaterjet | ISO 9001, AS9100 |
| KCSP Machine LLC (formerly Kansas City Screw Products) Milling, Turning, Welding · ISO 9001, AS9100 | Kansas City, MO | MillingTurningWelding | ISO 9001, AS9100 |
| Kelley-Tron Machine Co Milling, Turning | Harrisburg, PA | MillingTurning | - |
| King Precision Solutions Milling, Turning, Welding, EDM · ISO 9001, ITAR | Erie, PA | MillingTurningWeldingEDM | ISO 9001, ITAR |
| King Tek EDM & Precision Machining Milling, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, NADCAP | Anaheim, CA | MillingBendingWeldingEDM | ISO 9001, AS9100, ITAR, NADCAP |
| Krukemeier Machine Milling, Turning, EDM · AS9100, NADCAP | Indianapolis, IN | MillingTurningEDM | AS9100, NADCAP |
| Kyron Tool & Machine Co., Inc Milling, Turning, Welding | Columbus, OH | MillingTurningWelding | - |
| L&M machining center Milling, Turning, Metal AM · AS9100, ITAR | Tucson, AZ | MillingTurningMetal AM | AS9100, ITAR |
| La Machine Shop, Inc. Milling, Turning, Bending · ISO 9001, AS9100 | Ham Lake, MN | MillingTurningBending | ISO 9001, AS9100 |
| Lamjen Inc Milling, Turning, Welding, Stamping, Casting · ISO 9001 | Erie, PA | MillingTurningWeldingStampingCasting | ISO 9001 |
| Langill's General Machine Inc Milling, Welding | Sacramento, CA | MillingWelding | - |
| Lee Precision Machine Shop Inc. Milling, Turning, Bending, Welding, EDM · ISO 9001, ITAR | Athens, AL | MillingTurningBendingWeldingEDM | ISO 9001, ITAR |
| Loftis Steel & Aluminum, Inc. Milling, Laser, Waterjet | Nashville, TN | MillingLaserWaterjet | - |
| Logan Machine Co Milling, Turning, Bending, Welding | Akron, OH | MillingTurningBendingWelding | - |
| LT CNC Machining Inc. Milling, Turning, Welding · AS9100 | San Diego, CA | MillingTurningWelding | AS9100 |
| Luna's Sheet Metal Inc Milling, Turning, Bending, Laser, Welding | Santa Clara, CA | MillingTurningBendingLaserWelding | - |
| Luso Machine NJ, LLC Milling, Turning, Welding, EDM · ISO 9001 | Newark, NJ | MillingTurningWeldingEDM | ISO 9001 |
| M & J Manufacturing, Inc. Milling, Turning, EDM | Portland, OR | MillingTurningEDM | - |
| M B Steel Milling, Bending, Laser, Welding, Stamping | St. Louis, MO | MillingBendingLaserWeldingStamping | - |
| Mace Manufacturing Milling, Welding · ISO 9001, AS9100 | Englewood, CO | MillingWelding | ISO 9001, AS9100 |
| Mach3 Machining Milling, Turning, Welding · ISO 9001 | Cuyahoga Falls, OH | MillingTurningWelding | ISO 9001 |