| 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 |
| Southwest Precision Machining, L.L.C Milling, Turning, Swiss, Welding, Finishing | Tucson, AZ | MillingTurningSwissWeldingFinishing | - |
| Sparton Technology Corp Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100 | Hudson, NH | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100 |
| Speed Fabrication LLC Laser, Bending, Welding, Finishing | Perryville, MO | LaserBendingWeldingFinishing | - |
| Spring Creek Machining, Inc Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Finishing | Lowell, AR | MillingTurningWaterjetBendingWeldingEDMGrindingFinishing | - |
| Spsm Industries Inc Welding, Finishing | Burnsville, MN | WeldingFinishing | - |
| Square Deal Machining Inc Milling, Turning, Laser, Bending, Welding, Grinding, Finishing, Assembly | Marathon, NY | MillingTurningLaserBendingWeldingGrindingFinishingAssembly | - |
| ST Paul Brass Foundry Co Casting, Finishing · ISO 9001, AS9100, ITAR, CMMC | Saint Paul, MN | CastingFinishing | ISO 9001, AS9100, ITAR, CMMC |
| Standard Machine & Manufacturing, LLC Finishing · ITAR | Greenville, KY | Finishing | ITAR |
| Standard Machine, LLC Milling, Turning, Welding, Casting, Grinding, Finishing | Cleveland, OH | MillingTurningWeldingCastingGrindingFinishing | - |
| Starn Tool & Manufacturing Company Milling, Turning, EDM, Grinding, Finishing · ISO 9001, ITAR | Meadville, PA | MillingTurningEDMGrindingFinishing | ISO 9001, ITAR |
| Steen Machining, Inc Milling, Turning, Finishing | Westminster, CO | MillingTurningFinishing | - |
| Stone Machine Co. Inc Milling, Turning, Grinding, Finishing | Chester, NH | MillingTurningGrindingFinishing | - |
| Straton Industries Inc Milling, Turning, Stamping, EDM, Grinding, Finishing, Assembly · AS9100, ITAR, CMMC | Stratford, CT | MillingTurningStampingEDMGrindingFinishingAssembly | AS9100, ITAR, CMMC |
| Strong Forge & Fabrication, LLC Milling, Bending, Welding, Finishing | Batavia, NY | MillingBendingWeldingFinishing | - |
| Stuecklen Manufacturing Co Bending, Finishing | Franklin Park, IL | BendingFinishing | - |
| Sugar River Machine Inc Milling, Turning, Welding, Grinding, Finishing, Assembly | South Beloit, IL | MillingTurningWeldingGrindingFinishingAssembly | - |
| 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 | - |
| 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 Grinding Corp Milling, Turning, Grinding, Finishing | Antigo, WI | MillingTurningGrindingFinishing | - |
| Support Equipment Inc Milling, Turning, Welding, EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR | Escondido, CA | MillingTurningWeldingEDMFinishingAssembly | ISO 9001, AS9100, ITAR |
| Swanton Welding & Machining Co Inc Milling, Laser, Bending, Welding, Finishing, Assembly | Swanton, OH | MillingLaserBendingWeldingFinishingAssembly | - |
| 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 |
| Swiss Labs Machine and Engineering, Inc Milling, Turning, Swiss, Finishing · ISO 9001 | Franklin, IN | MillingTurningSwissFinishing | ISO 9001 |
| Swissturn/usa, Inc Milling, Turning, Swiss, Grinding, Finishing · ISO 9001, ITAR, CMMC | Oxford, MA | MillingTurningSwissGrindingFinishing | ISO 9001, ITAR, CMMC |
| SX Industries, Inc Casting, Finishing | Stoughton, MA | CastingFinishing | - |
| Sycamore Precision, Inc Milling, Casting, Finishing | Genoa, IL | MillingCastingFinishing | - |
| Tahl Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR, CMMC | Tucson, AZ | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR, CMMC |
| Team Engineering Inc Laser, Waterjet, Finishing · ISO 9001 | Mesa, AZ | LaserWaterjetFinishing | ISO 9001 |
| Tec Inc Milling, Turning, Swiss, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Frederick, MD | MillingTurningSwissLaserPunchingBendingWeldingFinishingAssembly | ISO 9001 |
| Tech Five Machining LLC Milling, Turning, Finishing · ISO 9001, AS9100, ITAR | Tempe, AZ | MillingTurningFinishing | ISO 9001, AS9100, ITAR |
| Tek Additions LLC Finishing | Wilmington, NC | Finishing | - |
| Texarkana Machine Inc Milling, Turning, Waterjet, Welding, Grinding, Finishing | Texarkana, TX | MillingTurningWaterjetWeldingGrindingFinishing | - |
| 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 | - |
| Tiger Precision Machining Milling, Turning, Welding, Finishing | Lodi, CA | MillingTurningWeldingFinishing | - |
| TNT Machining LLC Milling, Turning, Grinding, Finishing | Sumas, WA | MillingTurningGrindingFinishing | - |
| Tompkins Products, Inc Milling, Welding, Grinding, Finishing · IATF 16949 | Detroit, MI | MillingWeldingGrindingFinishing | IATF 16949 |
| Top Machining, Inc Milling, Turning, Welding, Finishing, Assembly · ISO 9001, AS9100, ITAR | Santa Clara, CA | MillingTurningWeldingFinishingAssembly | ISO 9001, AS9100, ITAR |
| Top Notch Machining, Inc Milling, Waterjet, Stamping, Finishing, Assembly · ISO 9001 | Gresham, OR | MillingWaterjetStampingFinishingAssembly | ISO 9001 |
| TR Manufacturing, LLC Milling, Turning, Swiss, Laser, Waterjet, Welding, Finishing · CMMC | Garrett, IN | MillingTurningSwissLaserWaterjetWeldingFinishing | CMMC |
| Trace Technologies, LLC Milling, Finishing | Epping, NH | MillingFinishing | - |
| Tri-Jet Precision Cutting Services LLC Milling, Turning, Laser, Waterjet, Welding, Finishing · ISO 9001 | Palmer, AK | MillingTurningLaserWaterjetWeldingFinishing | ISO 9001 |
| Trident Precision Manufacturing Inc Welding, Stamping, Finishing, Assembly · ISO 9001, AS9100, ITAR, ISO 13485 | Webster, NY | WeldingStampingFinishingAssembly | ISO 9001, AS9100, ITAR, ISO 13485 |
| Trinity Machining, LLC Milling, Turning, Bending, EDM, Grinding, Finishing · ISO 9001 | Grass Valley, CA | MillingTurningBendingEDMGrindingFinishing | ISO 9001 |
| Troupe Technologies LLC Milling, Turning, Laser, Waterjet, Punching, Welding, Finishing | Huntsville, AL | MillingTurningLaserWaterjetPunchingWeldingFinishing | - |
| Troy Innovative Instruments, Inc Milling, Turning, Swiss, Laser, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001, ITAR, ISO 13485 | Middlefield, OH | MillingTurningSwissLaserWeldingEDMGrindingFinishingAssembly | ISO 9001, ITAR, ISO 13485 |