| SJC Precision Inc Milling, Laser, Punching, Welding, Stamping, Grinding · ISO 9001, ITAR | Milpitas, CA | MillingLaserPunchingWeldingStampingGrinding | ISO 9001, ITAR |
| Skytop Machine and Tool, Inc Milling, Turning, Waterjet, Welding, Grinding | Port Matilda, PA | MillingTurningWaterjetWeldingGrinding | - |
| Soflo Machining Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing · ISO 9001, AS9100 | Coral Springs, FL | MillingTurningLaserWaterjetWeldingGrindingFinishing | ISO 9001, AS9100 |
| Sonic Aerospace Inc Milling, Turning, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Chandler, AZ | MillingTurningGrindingFinishingAssembly | ISO 9001, AS9100 |
| South Central Manufacturing Corp Milling, Turning, Welding, Grinding | Summersville, MO | MillingTurningWeldingGrinding | - |
| Southern Ohio Manufacturing Milling, Turning, Laser, Bending, Welding, Grinding, Finishing | Amelia, OH | MillingTurningLaserBendingWeldingGrindingFinishing | - |
| Southern Precision Machining Milling, Turning, Grinding, Finishing · ISO 9001, AS9100, ITAR | Shelbyville, TN | MillingTurningGrindingFinishing | ISO 9001, AS9100, ITAR |
| Specialty Machine Milling, Turning, Swiss, Laser, Bending, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Lago Vista, TX | MillingTurningSwissLaserBendingWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Specialty Tool & Die Company Inc Milling, Turning, Bending, Welding, Stamping, Grinding, Assembly | Kokomo, IN | MillingTurningBendingWeldingStampingGrindingAssembly | - |
| Spring Creek Machining, Inc Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Finishing | Lowell, AR | MillingTurningWaterjetBendingWeldingEDMGrindingFinishing | - |
| Square Deal Machining Inc Milling, Turning, Laser, Bending, Welding, Grinding, Finishing, Assembly | Marathon, NY | MillingTurningLaserBendingWeldingGrindingFinishingAssembly | - |
| Standard Machine, LLC Milling, Turning, Welding, Casting, Grinding, Finishing | Cleveland, OH | MillingTurningWeldingCastingGrindingFinishing | - |
| Stanfordville Machine & Manufacturing Co Inc Milling, Turning, Swiss, Welding, EDM, Grinding · ISO 9001, AS9100 | Poughkeepsie, NY | MillingTurningSwissWeldingEDMGrinding | ISO 9001, AS9100 |
| Stanton Precision Products L.L.C Milling, Turning, Swiss, Grinding · CMMC | Butler, NJ | MillingTurningSwissGrinding | CMMC |
| Starn Tool & Manufacturing Company Milling, Turning, EDM, Grinding, Finishing · ISO 9001, ITAR | Meadville, PA | MillingTurningEDMGrindingFinishing | ISO 9001, ITAR |
| Steelcrest Precision, Inc Milling, Turning, Swiss, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100 | Wauseon, OH | MillingTurningSwissWeldingEDMGrindingAssembly | ISO 9001, AS9100 |
| Steer Machine Tool and Die Corporation Milling, Turning, Welding, Grinding | Honesdale, PA | MillingTurningWeldingGrinding | - |
| Stellar Precision Components. Ltd Milling, Turning, EDM, Grinding · ISO 9001, AS9100 | Jeannette, PA | MillingTurningEDMGrinding | ISO 9001, AS9100 |
| Stephen J Hartman Milling, Turning, Welding, Grinding | Sykesville, MD | MillingTurningWeldingGrinding | - |
| Stephens Precision, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Bradford, VT | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Stone Machine Co. Inc Milling, Turning, Grinding, Finishing | Chester, NH | MillingTurningGrindingFinishing | - |
| Stork Precision Machining LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001, CMMC | Washington, MO | MillingTurningWeldingEDMGrinding | ISO 9001, CMMC |
| Straton Industries Inc Milling, Turning, Stamping, EDM, Grinding, Finishing, Assembly · AS9100, ITAR, CMMC | Stratford, CT | MillingTurningStampingEDMGrindingFinishingAssembly | AS9100, ITAR, CMMC |
| Streamline Machine Source Inc Milling, Laser, Waterjet, Grinding · ISO 9001 | Greenville, MI | MillingLaserWaterjetGrinding | ISO 9001 |
| Sugar River Machine Inc Milling, Turning, Welding, Grinding, Finishing, Assembly | South Beloit, IL | MillingTurningWeldingGrindingFinishingAssembly | - |
| Sulzer Machine & Manufacturing Inc Milling, Welding, Grinding · ISO 9001 | Mosinee, WI | MillingWeldingGrinding | ISO 9001 |
| Summit Machine Solutions LLC Milling, Welding, Grinding | Akron, OH | MillingWeldingGrinding | - |
| Sunnycor Inc Milling, Turning, Grinding, Assembly · AS9100, ITAR | Torrington, CT | MillingTurningGrindingAssembly | AS9100, ITAR |
| Sunset Industries Inc Milling, Turning, Swiss, Casting, EDM, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR, CMMC | Mentor, OH | MillingTurningSwissCastingEDMGrindingFinishingAssembly | ISO 9001, AS9100, ITAR, CMMC |
| Super Web Digital, Inc Milling, Turning, Welding, Grinding | West Babylon, NY | MillingTurningWeldingGrinding | - |
| Superior Grinding Corp Milling, Turning, Grinding, Finishing | Antigo, WI | MillingTurningGrindingFinishing | - |
| Superior Machining and Fabrication Inc Milling, Turning, Grinding, Assembly · ISO 9001, AS9100, ITAR | Muenster, TX | MillingTurningGrindingAssembly | ISO 9001, AS9100, ITAR |
| Superior Tooling Inc Milling, Turning, Swiss, Bending, Welding, Stamping, EDM, Grinding · ISO 9001 | Wapello, IA | MillingTurningSwissBendingWeldingStampingEDMGrinding | ISO 9001 |
| Surface Finishes Welding, Grinding · ITAR | Addison, IL | WeldingGrinding | ITAR |
| Swift Industries Inc Milling, Laser, Punching, Bending, Welding, Stamping, Grinding, Finishing, Assembly · ISO 9001 | Suwanee, GA | MillingLaserPunchingBendingWeldingStampingGrindingFinishingAssembly | ISO 9001 |
| Swiss Automation, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, ITAR, ISO 13485 | Barrington, IL | MillingTurningSwissGrindingFinishing | ISO 9001, ITAR, ISO 13485 |
| Swissturn/usa, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, ITAR, CMMC | Oxford, MA | MillingTurningSwissGrindingFinishing | ISO 9001, ITAR, CMMC |
| T.P. Engineering Inc Milling, Turning, Swiss, Welding, Grinding, Assembly · ISO 9001, ITAR, ISO 13485 | Danbury, CT | MillingTurningSwissWeldingGrindingAssembly | ISO 9001, ITAR, ISO 13485 |
| T&K Machine Milling, Turning, Welding, EDM, Grinding | Livermore, CA | MillingTurningWeldingEDMGrinding | - |
| Tahl Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR, CMMC | Tucson, AZ | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR, CMMC |
| Tanksley Machine & Tool, Inc Milling, Turning, Laser, Welding, EDM, Grinding · AS9100 | Decatur, AL | MillingTurningLaserWeldingEDMGrinding | AS9100 |
| Taylor Turning Inc Milling, Turning, Grinding | Wixom, MI | MillingTurningGrinding | - |
| Team Technologies Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100 | Albuquerque, NM | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, AS9100 |
| Technical Products Inc Milling, Turning, Laser, Grinding · ISO 9001 | West Bend, WI | MillingTurningLaserGrinding | ISO 9001 |
| Tecton Industries Inc Milling, Turning, Casting, Grinding · ISO 9001, AS9100 | Spencer, IA | MillingTurningCastingGrinding | ISO 9001, AS9100 |
| Tennessee Tool Works LLC Milling, Turning, Laser, Waterjet, Bending, Welding, Stamping, EDM, Grinding | Murfreesboro, TN | MillingTurningLaserWaterjetBendingWeldingStampingEDMGrinding | - |
| Texarkana Machine Inc Milling, Turning, Waterjet, Welding, Grinding, Finishing | Texarkana, TX | MillingTurningWaterjetWeldingGrindingFinishing | - |
| Thaler Machine Co LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100 | Springboro, OH | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100 |
| The Flinchbaugh Company, Inc Milling, Turning, Welding, EDM, Grinding, Finishing, Assembly | Manchester, PA | MillingTurningWeldingEDMGrindingFinishingAssembly | - |
| Thermo-Craft Engineering Corp Milling, Turning, Waterjet, Punching, Bending, Welding, Grinding, Assembly | Lynn, MA | MillingTurningWaterjetPunchingBendingWeldingGrindingAssembly | - |