| SMT Machine & Tool Milling, Turning, Welding, Casting | Green Bay, WI | MillingTurningWeldingCasting | - |
| Southern Metal Fabricators, Inc Welding, Casting | Albertville, AL | WeldingCasting | - |
| Spuncast Inc Casting · ISO 9001 | Watertown, WI | Casting | ISO 9001 |
| ST Paul Brass Foundry Co Casting, Finishing · ISO 9001, AS9100, ITAR, CMMC | Saint Paul, MN | CastingFinishing | ISO 9001, AS9100, ITAR, CMMC |
| Stampede Die Corp Milling, Turning, Waterjet, Welding, Casting, EDM | Wayland, MI | MillingTurningWaterjetWeldingCastingEDM | - |
| Summit Machining Co., Ltd Milling, Turning, Welding, Stamping, Casting, Finishing | Mogadore, OH | MillingTurningWeldingStampingCastingFinishing | - |
| Sunset Industries Inc Milling, Turning, Swiss, Casting, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, CMMC | Mentor, OH | MillingTurningSwissCastingEDMGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| T F E Company Inc Milling, Turning, Laser, Casting · ITAR | Brenham, TX | MillingTurningLaserCasting | ITAR |
| Tanfel, Inc Milling, Stamping, Casting · ISO 9001 | Scottsdale, AZ | MillingStampingCasting | ISO 9001 |
| Tennessee Tool & Engineering Inc Welding, Casting, Assembly · ISO 9001 | Oak Ridge, TN | WeldingCastingAssembly | ISO 9001 |
| The Lindgren Group Casting, Finishing · ITAR, NADCAP, CMMC | Minneapolis, MN | CastingFinishing | ITAR, NADCAP, CMMC |
| Think Variant Inc Milling, Turning, Laser, Bending, Welding, Casting, Metal AM | Phoenix, NY | MillingTurningLaserBendingWeldingCastingMetal AM | - |
| Toth Industries Inc Milling, Turning, Bending, Casting · ISO 9001 | Toledo, OH | MillingTurningBendingCasting | ISO 9001 |
| Trans Machine Technologies SC Milling, Turning, Bending, Laser, Welding, EDM, Casting · ISO 9001 | Greenville, SC | MillingTurningBendingLaserWeldingEDMCasting | ISO 9001 |
| Tucson CNC Machining, Inc. Milling, Turning, Bending, Casting | Tucson, AZ | MillingTurningBendingCasting | - |
| Walerko Tool & Engineering Milling, Turning, Casting · ISO 9001, AS9100 | Elkhart, IN | MillingTurningCasting | ISO 9001, AS9100 |
| Warner Bros, Foundry Co Welding, Casting | Roseville, MI | WeldingCasting | - |
| Wieland Techni-Cast Milling, Casting | South Gate, CA | MillingCasting | - |
| Withers Tool, Die & Manufacturing Company Milling, Turning, Welding, Casting, Grinding | Mableton, GA | MillingTurningWeldingCastingGrinding | - |
| Wolverine Bronze Co Welding, Casting | Roseville, MI | WeldingCasting | - |
| Yankee Casting Co, Inc Milling, Welding, Casting · AS9100, NADCAP | Enfield, CT | MillingWeldingCasting | AS9100, NADCAP |