| Seastrom Manufacturing Co Inc Milling, Turning, Laser, Waterjet, Stamping, Finishing, Assembly · ISO 9001 | Twin Falls, ID | MillingTurningLaserWaterjetStampingFinishingAssembly | ISO 9001 |
| Seconn Fabrication LLC Laser, Punching, Bending, Welding, Finishing | Waterford, CT | LaserPunchingBendingWeldingFinishing | - |
| Serrmi Products LLC Milling, Turning, Laser, Punching, Bending, Finishing | Pittsburg, KS | MillingTurningLaserPunchingBendingFinishing | - |
| Seven Star Marine Inc Milling, Turning, Waterjet, Bending, Welding, Finishing · ISO 9001 | Newport, RI | MillingTurningWaterjetBendingWeldingFinishing | ISO 9001 |
| Shamong Manufacturing Laser, Punching, Bending, Welding, Stamping, Grinding, Finishing, Assembly · AS9100, NADCAP | Shamong, NJ | LaserPunchingBendingWeldingStampingGrindingFinishingAssembly | AS9100, NADCAP |
| Shape Shifters Inc Milling, Waterjet, Bending, Welding, Stamping, Finishing | Bloomfield, IN | MillingWaterjetBendingWeldingStampingFinishing | - |
| Sharp Dimension Inc Milling, Turning, Bending, Welding, Grinding, Finishing, Assembly · ISO 9001, ITAR | Fremont, CA | MillingTurningBendingWeldingGrindingFinishingAssembly | ISO 9001, ITAR |
| Shieldcoat Technologies Inc Finishing, Assembly · ISO 9001, ITAR | Lufkin, TX | FinishingAssembly | ISO 9001, ITAR |
| Sifco Industries Inc Forging, Finishing, Assembly · ISO 9001, NADCAP | Cleveland, OH | ForgingFinishingAssembly | ISO 9001, NADCAP |
| Sintel Inc Laser, Punching, Bending, Welding, Finishing, Assembly | Spring Lake, MI | LaserPunchingBendingWeldingFinishingAssembly | - |
| SJK Machine LLC Milling, Turning, Waterjet, Welding, EDM, Finishing | Minerva, OH | MillingTurningWaterjetWeldingEDMFinishing | - |
| Sonic Aerospace Inc Milling, Turning, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Chandler, AZ | MillingTurningGrindingFinishingAssembly | ISO 9001, AS9100 |
| Sonic Manufacturing Corporation Milling, Welding, EDM, Grinding, Finishing, Assembly · AS9100, NADCAP | Elk Grove Village, IL | MillingWeldingEDMGrindingFinishingAssembly | AS9100, NADCAP |
| Soteria LLC Milling, Turning, Welding, Grinding, Finishing | Anniston, AL | MillingTurningWeldingGrindingFinishing | - |
| 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 | - |
| Spectrum Custom Molds & Manufacturing, Inc Milling, Turning, Laser, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001 | Palmetto, FL | MillingTurningLaserWeldingEDMGrindingFinishingAssembly | ISO 9001 |
| Speed Fabrication LLC Laser, Bending, Welding, Finishing | Perryville, MO | LaserBendingWeldingFinishing | - |
| SPM Milling, Turning, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001 | Portland, OR | MillingTurningWeldingEDMGrindingFinishingAssembly | ISO 9001 |
| Spring Creek Machining, Inc Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Finishing | Lowell, AR | MillingTurningWaterjetBendingWeldingEDMGrindingFinishing | - |
| Square One Coating Systems LLC Finishing · NADCAP | Oriskany, NY | Finishing | NADCAP |
| Standard Machine & Manufacturing, LLC Finishing · ITAR | Greenville, KY | Finishing | ITAR |
| 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 | - |
| Stellar Industries LLC Laser, Bending, Welding, Stamping, Finishing · ISO 9001 | Nappanee, IN | LaserBendingWeldingStampingFinishing | ISO 9001 |
| Stever Locke, Inc Turning, Stamping, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR | Honeoye Falls, NY | TurningStampingGrindingFinishingAssembly | ISO 9001, AS9100, ITAR |
| Stigtec Manufacturing Milling, Welding, EDM, Grinding, Finishing, Assembly | San Marcos, CA | MillingWeldingEDMGrindingFinishingAssembly | - |
| Straton Industries Inc Milling, Turning, Stamping, EDM, Grinding, Finishing, Assembly · AS9100, ITAR, CMMC | Stratford, CT | MillingTurningStampingEDMGrindingFinishingAssembly | AS9100, ITAR, CMMC |
| Strohwig Industries, Inc Milling, Turning, Casting, EDM, Grinding, Finishing, Assembly · ISO 9001, ITAR, CMMC | Richfield, WI | MillingTurningCastingEDMGrindingFinishingAssembly | ISO 9001, ITAR, CMMC |
| Strong Forge & Fabrication, LLC Milling, Bending, Welding, Finishing | Batavia, NY | MillingBendingWeldingFinishing | - |
| Sturdy Grinding & Machining Inc Grinding, Finishing · ISO 9001 | New Haven, MI | GrindingFinishing | ISO 9001 |
| Subtract LLC Milling, Turning, Swiss, Laser, Waterjet, Welding, EDM, Finishing | Muncie, IN | MillingTurningSwissLaserWaterjetWeldingEDMFinishing | - |
| Sullivan Precision Metal Finishing Finishing · AS9100, ITAR | Sullivan, MO | Finishing | AS9100, ITAR |
| Summit Machine Company Milling, Turning, Welding, Finishing · ISO 9001 | Alverton, PA | MillingTurningWeldingFinishing | ISO 9001 |
| Summit Products Inc Milling, Bending, Welding, Finishing | Altoona, IA | MillingBendingWeldingFinishing | - |
| Support Equipment Inc Milling, Turning, Welding, EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR | Escondido, CA | MillingTurningWeldingEDMFinishingAssembly | ISO 9001, AS9100, ITAR |
| Swift Industries Inc Milling, Laser, Punching, Bending, Welding, Stamping, Grinding, Finishing, Assembly · ISO 9001 | Suwanee, GA | MillingLaserPunchingBendingWeldingStampingGrindingFinishingAssembly | ISO 9001 |
| SX Industries, Inc Casting, Finishing | Stoughton, MA | CastingFinishing | - |
| Sycamore Precision, Inc Milling, Casting, Finishing | Genoa, IL | MillingCastingFinishing | - |
| T.R. Reed Enterprises Inc Milling, Turning, Finishing · ISO 9001, AS9100 | Ponder, TX | MillingTurningFinishing | ISO 9001, AS9100 |
| Tabet Manufacturing Co Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Norfolk, VA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| Tag Team Manufacturing Turning, Welding, Finishing · ISO 9001 | Parker, CO | TurningWeldingFinishing | ISO 9001 |
| Tam Metal Products Punching, Welding, Stamping, Finishing · NADCAP | Mahwah, NJ | PunchingWeldingStampingFinishing | NADCAP |
| 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 |
| Tech Met Inc Milling, Finishing · NADCAP | Glassport, PA | MillingFinishing | NADCAP |
| Techcraft Precision Milling, Finishing · AS9100, ITAR, CMMC | Bellingham, WA | MillingFinishing | AS9100, ITAR, CMMC |
| Tek Additions LLC Finishing | Wilmington, NC | Finishing | - |