| Steel Specialties Inc. Welding | El Paso, TX | Welding | - |
| Steelhead Composites, Inc Welding · ISO 9001, AS9100 | Golden, CO | Welding | ISO 9001, AS9100 |
| Stephens Precision, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Bradford, VT | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Sterling Machine Technologies Turning, Bending, Welding | Palmyra, PA | TurningBendingWelding | - |
| Steward Machine Co., Inc Turning, Welding, Assembly | Birmingham, AL | TurningWeldingAssembly | - |
| Stork Precision Machining LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001, CMMC | Washington, MO | MillingTurningWeldingEDMGrinding | ISO 9001, CMMC |
| Strickland Machine Co LLC Milling, Turning, Welding, Stamping, Grinding, Finishing, Assembly | North Chesterfield, VA | MillingTurningWeldingStampingGrindingFinishingAssembly | - |
| Structural Steel & Plate Fab Bending, Welding | North Salt Lake, UT | BendingWelding | - |
| Subtract LLC Milling, Turning, Swiss, Laser, Waterjet, Welding, EDM, Finishing | Muncie, IN | MillingTurningSwissLaserWaterjetWeldingEDMFinishing | - |
| Summit Machine Company Milling, Turning, Welding, Finishing · ISO 9001 | Alverton, PA | MillingTurningWeldingFinishing | ISO 9001 |
| Summit Machining Co., Ltd Milling, Turning, Welding, Stamping, Casting, Finishing | Mogadore, OH | MillingTurningWeldingStampingCastingFinishing | - |
| Sunspot Solutions LLC Welding | Lyons, IN | Welding | - |
| Super Web Digital, Inc Milling, Turning, Welding, Grinding | West Babylon, NY | MillingTurningWeldingGrinding | - |
| Superior Process Solutions Milling, Turning, Bending, Laser, Welding, Metal AM | Springfield, MO | MillingTurningBendingLaserWeldingMetal AM | - |
| Surface Finishes Welding, Grinding · ITAR | Addison, IL | WeldingGrinding | ITAR |
| Susquehanna Metal Work, LLC Milling, Bending, Welding, Stamping | Columbia, PA | MillingBendingWeldingStamping | - |
| Swan Island Sheet Metal Works Turning, Bending, Laser, Welding | Portland, OR | TurningBendingLaserWelding | - |
| Synergy Manufacturing Services LLC Welding, Assembly | Grafton, WI | WeldingAssembly | - |
| T & D Specialties Milling, Turning, Swiss, Welding, Finishing · ISO 9001 | Oxford, MA | MillingTurningSwissWeldingFinishing | ISO 9001 |
| T.P. Engineering Inc Milling, Turning, Swiss, Welding, Grinding, Assembly · ISO 9001, ITAR, ISO 13485 | Danbury, CT | MillingTurningSwissWeldingGrindingAssembly | ISO 9001, ITAR, ISO 13485 |
| Tabet Manufacturing Co Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Norfolk, VA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| Tam Metal Products Punching, Welding, Stamping, Finishing · NADCAP | Mahwah, NJ | PunchingWeldingStampingFinishing | NADCAP |
| Tampa Bay Machining Milling, Turning, Welding, EDM · ISO 9001, AS9100, ITAR | Tampa, FL | MillingTurningWeldingEDM | ISO 9001, AS9100, ITAR |
| Tampa Brass and Aluminum Corporation Milling, Turning, Welding, Casting, Assembly | Tampa, FL | MillingTurningWeldingCastingAssembly | - |
| Tarman Machine Company, Inc. Welding | Canal Winchester, OH | Welding | - |
| TCMS Inc Milling, Turning, Welding | Oklahoma City, OK | MillingTurningWelding | - |
| Technical Concepts LLC Milling, Turning, Laser, Bending, Welding | Hollywood, AL | MillingTurningLaserBendingWelding | - |
| Tecma Milling, Turning, Welding, Waterjet, EDM, Stamping, Casting · ISO 9001, AS9100, ITAR, NADCAP | Sacramento, CA | MillingTurningWeldingWaterjetEDMStampingCasting | ISO 9001, AS9100, ITAR, NADCAP |
| Tel-X Corporation Milling, Turning, Laser, Welding, Stamping, EDM, Finishing · ISO 9001, IATF 16949 | Garden City, MI | MillingTurningLaserWeldingStampingEDMFinishing | ISO 9001, IATF 16949 |
| Telcon Inc Welding, Assembly | Streetsboro, OH | WeldingAssembly | - |
| Teltron Engineering, Inc Laser, Punching, Bending, Welding, Assembly · AS9100, ITAR, CMMC | Taunton, MA | LaserPunchingBendingWeldingAssembly | AS9100, ITAR, CMMC |
| Tennessee Tool Works LLC Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding | Murfreesboro, TN | MillingTurningLaserWaterjetBendingWeldingStampingEDMGrinding | - |
| Texas Metal Specialty Co Laser, Welding, Waterjet | Houston, TX | LaserWeldingWaterjet | - |
| The Bennu Group Inc Milling, Turning, Waterjet, Welding, Finishing · ISO 9001 | South Holland, IL | MillingTurningWaterjetWeldingFinishing | ISO 9001 |
| The Flinchbaugh Company, Inc Milling, Turning, Welding, EDM, Grinding, Finishing, Assembly | Manchester, PA | MillingTurningWeldingEDMGrindingFinishingAssembly | - |
| The PDI Group Welding, Finishing · ISO 9001, AS9100, ITAR, CMMC | Sparta, NJ | WeldingFinishing | ISO 9001, AS9100, ITAR, CMMC |
| The Progress Group, Inc Turning, Welding, Assembly · ISO 9001 | Schererville, IN | TurningWeldingAssembly | ISO 9001 |
| Theonics Milling, Turning, Bending, Welding, EDM · AS9100, ITAR, ISO 13485 | Huntsville, AL | MillingTurningBendingWeldingEDM | AS9100, ITAR, ISO 13485 |
| Thermo-Craft Engineering Corp Milling, Turning, Waterjet, Punching, Bending, Welding, Grinding, Assembly | Lynn, MA | MillingTurningWaterjetPunchingBendingWeldingGrindingAssembly | - |
| Third Reef Machining and Engineering Ltd. Co Milling, Bending, Welding, Finishing | Cottonwood Heights, UT | MillingBendingWeldingFinishing | - |
| Thorough Built LLC Bending, Laser, Welding | Chattanooga, TN | BendingLaserWelding | - |
| Three Rivers Precision, LLC Welding, Assembly · ISO 9001 | East Liberty, PA | WeldingAssembly | ISO 9001 |
| Tin-Mar, Inc Milling, Turning, Waterjet, Welding, EDM · ISO 9001, AS9100 | Huntsville, AL | MillingTurningWaterjetWeldingEDM | ISO 9001, AS9100 |
| TMS Inc Milling, Laser, Punching, Bending, Welding, Grinding, Finishing, Assembly | New Berlin, WI | MillingLaserPunchingBendingWeldingGrindingFinishingAssembly | - |
| Tompkins Products, Inc Milling, Welding, Grinding, Finishing · IATF 16949 | Detroit, MI | MillingWeldingGrindingFinishing | IATF 16949 |
| Toolco Inc Milling, Turning, Welding, Stamping, EDM, Grinding | Owensboro, KY | MillingTurningWeldingStampingEDMGrinding | - |
| Toolex Corp Milling, Welding, EDM, Grinding, Finishing | Addison, IL | MillingWeldingEDMGrindingFinishing | - |
| Top Notch EDM Service LLC Milling, Welding, EDM | Conroe, TX | MillingWeldingEDM | - |
| TR Manufacturing, LLC Milling, Turning, Swiss, Laser, Waterjet, Welding, Finishing · CMMC | Garrett, IN | MillingTurningSwissLaserWaterjetWeldingFinishing | CMMC |
| Trade Tech Inc Milling, Turning, Waterjet, Welding · ISO 9001, ITAR, CMMC | Hartford, WI | MillingTurningWaterjetWelding | ISO 9001, ITAR, CMMC |