| Schmid Tool & Engineering Corp Milling, Turning, Swiss, Stamping, Grinding, Finishing, Assembly · ISO 9001, ITAR | Villa Park, IL | MillingTurningSwissStampingGrindingFinishingAssembly | ISO 9001, ITAR |
| Schulte Corporation Milling, Turning, Welding, Finishing · NADCAP | San Clemente, CA | MillingTurningWeldingFinishing | NADCAP |
| Seminole Metal Finishing, Inc Finishing | Altamonte Springs, FL | Finishing | - |
| Sequoia Machine Works LLC Milling, Turning, Laser, Punching, Welding, Finishing | Sandy, OR | MillingTurningLaserPunchingWeldingFinishing | - |
| Serrmi Products LLC Milling, Turning, Laser, Punching, Bending, Finishing | Pittsburg, KS | MillingTurningLaserPunchingBendingFinishing | - |
| Sharp Dimension Inc Milling, Turning, Bending, Welding, Grinding, Finishing, Assembly · ISO 9001, ITAR | Fremont, CA | MillingTurningBendingWeldingGrindingFinishingAssembly | ISO 9001, ITAR |
| Sifco Industries Inc Forging, Finishing, Assembly · ISO 9001, NADCAP | Cleveland, OH | ForgingFinishingAssembly | ISO 9001, NADCAP |
| Silver Creek Machine Ltd Milling, Turning, Bending, Finishing · ISO 9001 | Fort Worth, TX | MillingTurningBendingFinishing | ISO 9001 |
| SJK Machine LLC Milling, Turning, Waterjet, Welding, EDM, Finishing | Minerva, OH | MillingTurningWaterjetWeldingEDMFinishing | - |
| Smith Metal, LLC Milling, Turning, Swiss, Laser, Waterjet, Bending, Welding, EDM, Grinding, Finishing · ISO 9001 | Augusta, MI | MillingTurningSwissLaserWaterjetBendingWeldingEDMGrindingFinishing | ISO 9001 |
| Snowline Engineering Laser, Waterjet, Welding, Finishing · ISO 9001, AS9100, NADCAP | Cameron Park, CA | LaserWaterjetWeldingFinishing | ISO 9001, AS9100, NADCAP |
| Sonic Aerospace Inc Milling, Turning, Grinding, Finishing, Assembly · ISO 9001, AS9100 | Chandler, AZ | MillingTurningGrindingFinishingAssembly | ISO 9001, AS9100 |
| Southern Precision Machining Milling, Turning, Grinding, Finishing · ISO 9001, AS9100, ITAR | Shelbyville, TN | MillingTurningGrindingFinishing | ISO 9001, AS9100, ITAR |
| SP Manufacturing Inc Milling, Turning, Welding, Finishing · ISO 9001, AS9100 | Livermore, CA | MillingTurningWeldingFinishing | ISO 9001, AS9100 |
| Spectrum Custom Molds & Manufacturing, Inc Milling, Turning, Laser, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001 | Palmetto, FL | MillingTurningLaserWeldingEDMGrindingFinishingAssembly | ISO 9001 |
| Spsm Industries Inc Welding, Finishing | Burnsville, MN | WeldingFinishing | - |
| Square One Coating Systems LLC Finishing · NADCAP | Oriskany, NY | Finishing | NADCAP |
| 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 | - |
| Stever Locke, Inc Turning, Stamping, Grinding, Finishing, Assembly · ISO 9001, AS9100, ITAR | Honeoye Falls, NY | TurningStampingGrindingFinishingAssembly | ISO 9001, AS9100, ITAR |
| Stone Machine Co. Inc Milling, Turning, Grinding, Finishing | Chester, NH | MillingTurningGrindingFinishing | - |
| Straitek, LLC Milling, Bending, Finishing · ITAR, ISO 13485 | Danbury, CT | MillingBendingFinishing | ITAR, ISO 13485 |
| Strom Manufacturing, LLC Milling, Turning, Finishing, Assembly · ISO 9001 | North Plains, OR | MillingTurningFinishingAssembly | ISO 9001 |
| Sturdy Grinding & Machining Inc Grinding, Finishing · ISO 9001 | New Haven, MI | GrindingFinishing | ISO 9001 |
| Sullivan Precision Metal Finishing Finishing · AS9100, ITAR | Sullivan, MO | Finishing | AS9100, ITAR |
| Summit Products Inc Milling, Bending, Welding, Finishing | Altoona, IA | MillingBendingWeldingFinishing | - |
| 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 | - |
| 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 | - |
| Systems Powered Manufacturing, LLC Grinding, Finishing, Assembly | Saint Charles, IL | GrindingFinishingAssembly | - |
| T & T Metals Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001 | Covina, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001 |
| T.e.t. Mfg. Co Inc Milling, Grinding, Finishing | Middlefield, CT | MillingGrindingFinishing | - |
| Tahl Inc Milling, Turning, Welding, EDM, Grinding, Finishing · ISO 9001, ITAR, CMMC | Tucson, AZ | MillingTurningWeldingEDMGrindingFinishing | ISO 9001, ITAR, CMMC |
| 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 |
| 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 Part Company, LLC Milling, Laser, Punching, Bending, Stamping, Metal AM, Finishing | Acworth, GA | MillingLaserPunchingBendingStampingMetal AMFinishing | - |
| The PDI Group Welding, Finishing · ISO 9001, AS9100, ITAR, CMMC | Sparta, NJ | WeldingFinishing | ISO 9001, AS9100, ITAR, CMMC |
| Theta Plate Inc Finishing · ISO 9001, ITAR | Albuquerque, NM | Finishing | ISO 9001, ITAR |
| TMF Inc Milling, Turning, Welding, Finishing, Assembly · ISO 9001, AS9100, ITAR, NADCAP | Poulsbo, WA | MillingTurningWeldingFinishingAssembly | ISO 9001, AS9100, ITAR, NADCAP |
| TMS Inc Milling, Laser, Punching, Bending, Welding, Grinding, Finishing, Assembly | New Berlin, WI | MillingLaserPunchingBendingWeldingGrindingFinishingAssembly | - |
| 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 Notch Machining, Inc Milling, Waterjet, Stamping, Finishing, Assembly · ISO 9001 | Gresham, OR | MillingWaterjetStampingFinishingAssembly | ISO 9001 |
| Topocut, LLC Milling, Laser, Bending, Finishing | Berthoud, CO | MillingLaserBendingFinishing | - |