| Sse Steel Fabrication Milling, Turning, Bending, Welding | Saint Bernard, LA | MillingTurningBendingWelding | - |
| 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 | - |
| Standard Machine, LLC Milling, Turning, Welding, Casting, Grinding, Finishing | Cleveland, OH | MillingTurningWeldingCastingGrindingFinishing | - |
| Stone Machine Co. Inc Milling, Turning, Grinding, Finishing | Chester, NH | MillingTurningGrindingFinishing | - |
| Strohwig Industries, Inc Milling, Turning, Casting, EDM, Grinding, Finishing, Assembly · ISO 9001, ITAR, CMMC | Richfield, WI | MillingTurningCastingEDMGrindingFinishingAssembly | ISO 9001, ITAR, CMMC |
| Sulzer Machine & Manufacturing Inc Milling, Welding, Grinding · ISO 9001 | Mosinee, WI | MillingWeldingGrinding | ISO 9001 |
| 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 |
| Superior Tooling Inc Milling, Turning, Swiss, Bending, Welding, Stamping, EDM, Grinding · ISO 9001 | Wapello, IA | MillingTurningSwissBendingWeldingStampingEDMGrinding | ISO 9001 |
| SX Industries, Inc Casting, Finishing | Stoughton, MA | CastingFinishing | - |
| Sycamore Precision, Inc Milling, Casting, Finishing | Genoa, IL | MillingCastingFinishing | - |
| Sylvester Sheet Metal Bending, Welding | Manchester, NH | BendingWelding | - |
| T F E Company Inc Milling, Turning, Laser, Casting · ITAR | Brenham, TX | MillingTurningLaserCasting | ITAR |
| Tampa Brass and Aluminum Corporation Milling, Turning, Welding, Casting, Assembly | Tampa, FL | MillingTurningWeldingCastingAssembly | - |
| Tanfel, Inc Milling, Stamping, Casting · ISO 9001 | Scottsdale, AZ | MillingStampingCasting | ISO 9001 |
| Tecma Milling, Turning, Welding, Waterjet, EDM, Stamping, Casting · ISO 9001, AS9100, ITAR, NADCAP | Sacramento, CA | MillingTurningWeldingWaterjetEDMStampingCasting | ISO 9001, AS9100, ITAR, NADCAP |
| Tecton Industries Inc Milling, Turning, Casting, Grinding · ISO 9001, AS9100 | Spencer, IA | MillingTurningCastingGrinding | ISO 9001, AS9100 |
| Tektonics Design Group LLC Milling, Turning, Casting | Richmond, VA | MillingTurningCasting | - |
| 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 |
| Thermo-Craft Engineering Corp Milling, Turning, Waterjet, Punching, Bending, Welding, Grinding, Assembly | Lynn, MA | MillingTurningWaterjetPunchingBendingWeldingGrindingAssembly | - |
| 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 |
| Treske Precision Machining Inc Milling, Assembly | Sherwood, OR | MillingAssembly | - |
| Trumbull Foundry and Alloy Inc Milling, Casting | Niles, OH | MillingCasting | - |
| Tucson CNC Machining, Inc. Milling, Turning, Bending, Casting | Tucson, AZ | MillingTurningBendingCasting | - |
| Turntec Manufacturing Milling, Turning, Welding, Grinding | Mills, WY | MillingTurningWeldingGrinding | - |
| Ultimate Manufacturing, Inc Milling, Turning, Grinding | Oakland Park, FL | MillingTurningGrinding | - |
| Ultrastratech LLC Milling, Turning, Bending, Stamping · CMMC | Tucson, AZ | MillingTurningBendingStamping | CMMC |
| United Grinding & Machine Co Milling, Turning, Bending, Laser, Welding, Waterjet, EDM, Casting · ISO 9001 | Canton, OH | MillingTurningBendingLaserWeldingWaterjetEDMCasting | ISO 9001 |
| United Sheetmetal Inc Laser, Punching, Welding, Stamping, Casting, EDM, Finishing · ISO 9001 | Fremont, CA | LaserPunchingWeldingStampingCastingEDMFinishing | ISO 9001 |
| US Aluminum Castings Milling, Turning, Casting, Grinding, Finishing, Assembly · ISO 9001, ITAR, NADCAP, IATF 16949 | Entiat, WA | MillingTurningCastingGrindingFinishingAssembly | ISO 9001, ITAR, NADCAP, IATF 16949 |
| Vangor Engineering Corporation, the Milling, Swiss, Casting · AS9100 | Oxford, CT | MillingSwissCasting | AS9100 |
| Vantage Manufacturing & Assembly LLC Milling, Turning, Laser, Welding, Assembly | Poughkeepsie, NY | MillingTurningLaserWeldingAssembly | - |
| Walerko Tool & Engineering Milling, Turning, Casting · ISO 9001, AS9100 | Elkhart, IN | MillingTurningCasting | ISO 9001, AS9100 |
| Warner Bros, Foundry Co Welding, Casting | Roseville, MI | WeldingCasting | - |
| Wayne Integrated Technologies Corp Milling, Bending, Welding, Assembly · ISO 9001, AS9100 | Edgewood, NY | MillingBendingWeldingAssembly | ISO 9001, AS9100 |
| Wieland Techni-Cast Milling, Casting | South Gate, CA | MillingCasting | - |
| Wiemann Metalcraft Bending, Laser, Welding, Casting | Tulsa, OK | BendingLaserWeldingCasting | - |
| 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 |