| Quantum Machining & Design Inc. Bending, Laser, Welding | Fresno, CA | BendingLaserWelding | - |
| R & R Manufacturing Milling, Turning, Welding, Waterjet | Hillsboro, OR | MillingTurningWeldingWaterjet | - |
| Rand Machine Works Milling, Turning, Bending, Welding | Fresno, CA | MillingTurningBendingWelding | - |
| Ravelin Defense Milling, Turning, Bending, Laser, Welding, Waterjet · ISO 9001, AS9100, ITAR, CMMC | Green Bay, WI | MillingTurningBendingLaserWeldingWaterjet | ISO 9001, AS9100, ITAR, CMMC |
| Reyco Precision Machining Welding, Metal AM · ISO 9001, AS9100 | Englewood, CO | WeldingMetal AM | ISO 9001, AS9100 |
| RivCut Milling, Turning, Bending, Metal AM · ISO 9001, AS9100, ITAR | Union City, CA | MillingTurningBendingMetal AM | ISO 9001, AS9100, ITAR |
| RJ Enterprises Milling, Turning, EDM · ISO 9001, AS9100, ITAR | Gardena, CA | MillingTurningEDM | ISO 9001, AS9100, ITAR |
| RJC Manufacturing Services LLC Milling, Turning, Bending, Welding | Irwin, PA | MillingTurningBendingWelding | - |
| S&W Precision Machining LLC Milling, Turning · ISO 9001, AS9100, ITAR, CMMC | Commerce City, CO | MillingTurning | ISO 9001, AS9100, ITAR, CMMC |
| Seaberg Industries Turning, Bending, Laser, Welding · ISO 9001 | Davenport, IA | TurningBendingLaserWelding | ISO 9001 |
| Seal Tex Welding | Dallas, TX | Welding | - |
| Seattle Makers Laser, Welding, Metal AM | Seattle, WA | LaserWeldingMetal AM | - |
| Selway Machine Tool Co Inc Milling, Turning, Metal AM | Salt Lake City, UT | MillingTurningMetal AM | - |
| Shamrock Machining Inc Milling, Turning, Bending, Laser, Welding · ISO 9001 | Spokane Valley, WA | MillingTurningBendingLaserWelding | ISO 9001 |
| Shamrock Precision Milling, Turning, Bending · ISO 9001, AS9100 | Dallas, TX | MillingTurningBending | ISO 9001, AS9100 |
| Sharp Tooling Company Milling, Turning, Bending, Welding, Waterjet, EDM, Stamping, Metal AM | Buffalo, NY | MillingTurningBendingWeldingWaterjetEDMStampingMetal AM | - |
| Sheet Metal Specialists (SMS Fabrications, Inc.) Bending, Laser, Welding, Waterjet · ISO 9001 | Riverside, CA | BendingLaserWeldingWaterjet | ISO 9001 |
| Slim Haney Machining Inc Milling, Turning, Welding | Tulsa, OK | MillingTurningWelding | - |
| SMT Machine & Tool Milling, Turning, Welding, Casting | Green Bay, WI | MillingTurningWeldingCasting | - |
| Solvers Manufacturing Turning, Bending, Welding | Springfield, NE | TurningBendingWelding | - |
| Specialty Metal Fabricators Bending, Welding | Portland, OR | BendingWelding | - |
| Specialty Precision Machining Milling, Turning, Laser · ISO 9001 | Stockton, CA | MillingTurningLaser | ISO 9001 |
| State Steel of Omaha Bending, Laser | Omaha, NE | BendingLaser | - |
| Steel Plate Fabricators Milling, Turning, Bending, Laser, Welding, Waterjet, Metal AM | Knoxville, TN | MillingTurningBendingLaserWeldingWaterjetMetal AM | - |
| Superior Process Solutions Milling, Turning, Bending, Laser, Welding, Metal AM | Springfield, MO | MillingTurningBendingLaserWeldingMetal AM | - |
| Swan Island Sheet Metal Works Turning, Bending, Laser, Welding | Portland, OR | TurningBendingLaserWelding | - |
| Swiss Technologies Inc. Milling, Turning, Welding, Stamping · ISO 9001 | Knoxville, TN | MillingTurningWeldingStamping | ISO 9001 |
| Tampa Bay Machining Milling, Turning, Welding, EDM · ISO 9001, AS9100, ITAR | Tampa, FL | MillingTurningWeldingEDM | ISO 9001, AS9100, ITAR |
| TBC Metalworks Bending, Laser, Welding | Green Bay, WI | BendingLaserWelding | - |
| Tecma Milling, Turning, Welding, Waterjet, EDM, Stamping, Casting · ISO 9001, AS9100, ITAR, NADCAP | Sacramento, CA | MillingTurningWeldingWaterjetEDMStampingCasting | ISO 9001, AS9100, ITAR, NADCAP |
| Temco Precision Machining Milling, EDM · ISO 9001, AS9100 | Manchester, NH | MillingEDM | ISO 9001, AS9100 |
| Teton Machine Co Milling, Turning · ISO 9001, AS9100, ITAR | Payette, ID | MillingTurning | ISO 9001, AS9100, ITAR |
| Texas Metal Specialty Co Laser, Welding, Waterjet | Houston, TX | LaserWeldingWaterjet | - |
| Thomason Machine Works Inc Milling, Turning, EDM · ISO 9001 | Rockford, IL | MillingTurningEDM | ISO 9001 |
| Thompson-Mathis Metal Mfg. Bending, Welding | Dallas, TX | BendingWelding | - |
| Toledo Metal Spinning Company Milling, Bending, Laser, Welding, Stamping · ISO 9001 | Toledo, OH | MillingBendingLaserWeldingStamping | ISO 9001 |
| Toron Manufacturing Milling, Welding | Elkhart, IN | MillingWelding | - |
| Trans Machine Technologies SC Milling, Turning, Bending, Laser, Welding, EDM, Casting · ISO 9001 | Greenville, SC | MillingTurningBendingLaserWeldingEDMCasting | ISO 9001 |
| Trans Tec Machine Laser, Welding, Waterjet · ISO 9001, AS9100 | Houston, TX | LaserWeldingWaterjet | ISO 9001, AS9100 |
| Tri Precision Sheetmetal, Inc. Bending, Laser, Welding · ISO 9001, AS9100 | Anaheim, CA | BendingLaserWelding | ISO 9001, AS9100 |
| Tri-Gon Precision, Inc. Milling, Turning, Welding, EDM | Colorado Springs, CO | MillingTurningWeldingEDM | - |
| Tri-Tec Industries Milling, Turning, Welding | Charlotte, NC | MillingTurningWelding | - |
| Triple E Machine Inc Turning, Laser, Welding, Waterjet, EDM | Appleton, WI | TurningLaserWeldingWaterjetEDM | - |
| True FAB and Powder Turning, Bending, Laser, Welding | Reno, NV | TurningBendingLaserWelding | - |
| Tucson CNC Machining, Inc. Milling, Turning, Bending, Casting | Tucson, AZ | MillingTurningBendingCasting | - |
| United Grinding & Machine Co Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting · ISO 9001 | Canton, OH | MillingTurningBendingLaserWeldingWaterjetEDMCasting | ISO 9001 |
| United Machine & Tool Milling, Turning, Laser, Welding · ISO 9001 | Goodlettsville, TN | MillingTurningLaserWelding | ISO 9001 |
| United Precision Machining Milling, Turning | Minneapolis, MN | MillingTurning | - |
| United Western Industries Inc. Milling, Bending, Laser, Welding, Stamping · IATF 16949 | Fresno, CA | MillingBendingLaserWeldingStamping | IATF 16949 |
| Upright Steel Fabricators Bending, Laser, Welding, Waterjet | Cleveland, OH | BendingLaserWeldingWaterjet | - |