| Hamilton Machine Co. Milling, Turning, Bending, Welding | Nashville, TN | MillingTurningBendingWelding | - |
| Hammer MetalWerks Bending, Laser, Welding | Indianapolis, IN | BendingLaserWelding | - |
| Hanset Stainless Inc Welding | Portland, OR | Welding | - |
| Harbor Fab Welding | Fort Worth, TX | Welding | - |
| Harvey Brothers Inc Bending, Welding | Cincinnati, OH | BendingWelding | - |
| HG Metals Bending, Welding | Indianapolis, IN | BendingWelding | - |
| HMF Corporation Bending, Laser, Welding | Anaheim, CA | BendingLaserWelding | - |
| HollyFab Turning, Bending, Laser, Welding, Waterjet | Addison, TX | TurningBendingLaserWeldingWaterjet | - |
| Industrial Fabricators Milling, Turning, Bending, Welding, Waterjet | Corpus Christi, TX | MillingTurningBendingWeldingWaterjet | - |
| Innovated Metal Fabrication, Inc Turning, Bending, Laser, Welding | Maplewood, MN | TurningBendingLaserWelding | - |
| Innovation Alley Milling, Turning, Bending, Welding | Fresno, CA | MillingTurningBendingWelding | - |
| IntoMetal Bending, Laser, Welding, Metal AM | Lincoln, NE | BendingLaserWeldingMetal AM | - |
| IPMI Manufacturing & Engineering Milling, Turning, Welding | Buckner, MO | MillingTurningWelding | - |
| IronStrong Metal Fabrication LLC Milling, Bending, Laser, Welding | Lancaster, PA | MillingBendingLaserWelding | - |
| J E Fifer Sheet Metal Fabricators Inc Bending, Laser, Welding | Richmond, VA | BendingLaserWelding | - |
| JD Machine Milling, Turning, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningBendingWeldingEDM | ISO 9001, AS9100, ITAR, CMMC |
| Jet Speed Metals Bending, Welding | Westbrook, ME | BendingWelding | - |
| Jewett Machine Milling, Turning, Welding · ISO 9001 | Richmond, VA | MillingTurningWelding | ISO 9001 |
| John W. McDougall Co. Bending, Laser, Welding · ISO 9001 | Nashville, TN | BendingLaserWelding | ISO 9001 |
| Jones & Lockhart Fabrication LLC Bending, Welding | St. Louis, MO | BendingWelding | - |
| 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 |
| KBM Industries Bending, Welding | Mechanicsburg, PA | BendingWelding | - |
| Kenney Industries, Inc. Bending, Welding · ISO 9001, NADCAP | Dallas, TX | BendingWelding | ISO 9001, NADCAP |
| King Tek EDM & Precision Machining Milling, Bending, Welding, EDM · ISO 9001, AS9100, ITAR, NADCAP | Anaheim, CA | MillingBendingWeldingEDM | ISO 9001, AS9100, ITAR, NADCAP |
| Kinney Manufacturing, LLC Bending, Laser, Welding, Metal AM | Lincoln, NE | BendingLaserWeldingMetal AM | - |
| Kyron Tool & Machine Co., Inc Milling, Turning, Welding | Columbus, OH | MillingTurningWelding | - |
| Lamjen Inc Milling, Turning, Welding, Stamping, Casting · ISO 9001 | Erie, PA | MillingTurningWeldingStampingCasting | ISO 9001 |
| Lawrence Fabric & Metal Structures, Inc. Welding · ISO 9001 | St. Louis, MO | Welding | ISO 9001 |
| Laystrom Manufacturing Company Bending, Laser, Welding | Chicago, IL | BendingLaserWelding | - |
| Lee Precision Machine Shop Inc. Milling, Turning, Bending, Welding, EDM · ISO 9001, ITAR | Athens, AL | MillingTurningBendingWeldingEDM | ISO 9001, ITAR |
| Logan Machine Co Milling, Turning, Bending, Welding | Akron, OH | MillingTurningBendingWelding | - |
| Lorraine Machine Inc Turning, Welding · ISO 9001 | Greenville, SC | TurningWelding | ISO 9001 |
| LR Design+Build Laser, Welding, Metal AM | Columbus, OH | LaserWeldingMetal AM | - |
| 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 7 Technologies Bending, Welding · ISO 9001 | Youngstown, OH | BendingWelding | ISO 9001 |
| M&M Metals Inc. Bending, Laser, Welding | San Antonio, TX | BendingLaserWelding | - |
| Machine Service Inc Welding · ISO 9001 | Green Bay, WI | Welding | ISO 9001 |
| Machine Time Inc Milling, Turning, Bending, Welding · ISO 9001, AS9100 | Nicholasville, KY | MillingTurningBendingWelding | ISO 9001, AS9100 |
| Machined Products Co Turning, Welding · ISO 9001 | Lancaster, PA | TurningWelding | ISO 9001 |
| Madden Fabrication Milling, Welding | Portland, OR | MillingWelding | - |
| Majestic Metals by Fathom Manufacturing Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting, Metal AM · ISO 9001, AS9100, ITAR, ISO 13485 | Denver, CO | MillingTurningBendingLaserWeldingWaterjetEDMCastingMetal AM | ISO 9001, AS9100, ITAR, ISO 13485 |
| Major Tool & Machine Milling, Turning, Welding · ISO 9001, AS9100, NADCAP | Indianapolis, IN | MillingTurningWelding | ISO 9001, AS9100, NADCAP |
| Maria Custom Sheet Metal Bending, Welding | Englewood, CO | BendingWelding | - |
| Mark One Metal Works Turning, Bending, Welding | Sparks, NV | TurningBendingWelding | - |
| Master Metal Products Co Bending, Welding | San Jose, CA | BendingWelding | - |
| Mat-Tech Machining Milling, Turning, Welding | Milwaukee, WI | MillingTurningWelding | - |
| Maumee Valley Fabricators Turning, Welding | Toledo, OH | TurningWelding | - |
| McAlpin Industries Inc. Milling, Bending, Laser, Welding, Stamping | Rochester, NY | MillingBendingLaserWeldingStamping | - |