| Richards Sheet Metal Turning, Bending, Laser, Welding, Stamping · ISO 9001 | Ogden, UT | TurningBendingLaserWeldingStamping | ISO 9001 |
| Rossetti Galaxy Enterprises, Inc Laser, Waterjet, Welding · ISO 9001 | Rothsay, MN | LaserWaterjetWelding | ISO 9001 |
| Royal Coatings Grinding, Finishing | Simi Valley, CA | GrindingFinishing | - |
| Roysters Machine Shop LLC Milling, Turning, Waterjet, Welding, Stamping, EDM · ISO 9001 | Henderson, KY | MillingTurningWaterjetWeldingStampingEDM | ISO 9001 |
| S & H Machine, Inc Milling, Turning, Assembly · ISO 9001, AS9100, ITAR | Burbank, CA | MillingTurningAssembly | ISO 9001, AS9100, ITAR |
| S & S Tool & Machine Co Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100, ITAR | Louisville, KY | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100, ITAR |
| S&W Precision Machining LLC Milling, Turning · ISO 9001, AS9100, ITAR, CMMC | Commerce City, CO | MillingTurning | ISO 9001, AS9100, ITAR, CMMC |
| Sadler Machine Co Inc Welding · ISO 9001 | Cedar Rapids, IA | Welding | ISO 9001 |
| Salsa Prototype Specialties Milling, Turning, Waterjet · ISO 9001 | Ventura, CA | MillingTurningWaterjet | ISO 9001 |
| Sapphire Metal Finishing, Inc Finishing · ISO 9001, NADCAP | Caldwell, ID | Finishing | ISO 9001, NADCAP |
| Schred Machine Company, Inc Milling, Turning · AS9100 | Warminster, PA | MillingTurning | AS9100 |
| Seastrom Manufacturing Co Inc Milling, Turning, Laser, Waterjet, Stamping, Finishing, Assembly · ISO 9001 | Twin Falls, ID | MillingTurningLaserWaterjetStampingFinishingAssembly | ISO 9001 |
| Shamrock Precision Milling, Turning, Bending · ISO 9001, AS9100 | Dallas, TX | MillingTurningBending | ISO 9001, AS9100 |
| Sharp Tool Manufacturing Milling, Turning, Welding · ISO 9001, AS9100, ITAR, CMMC | Ogden, UT | MillingTurningWelding | ISO 9001, AS9100, ITAR, CMMC |
| Sheet Metal Specialists (SMS Fabrications, Inc.) Bending, Laser, Welding, Waterjet · ISO 9001 | Riverside, CA | BendingLaserWeldingWaterjet | ISO 9001 |
| Si Aerospace Inc Milling · ISO 9001, AS9100, ITAR | Van Nuys, CA | Milling | ISO 9001, AS9100, ITAR |
| Skamar Machine Milling, Turning · ISO 9001 | Cleveland, OH | MillingTurning | ISO 9001 |
| Skydrive LLC Milling · ISO 9001, AS9100, ITAR | Collierville, TN | Milling | ISO 9001, AS9100, ITAR |
| Snyder Industries Inc Milling, Turning, Welding · ISO 9001 | Tonawanda, NY | MillingTurningWelding | ISO 9001 |
| South Eastern Machining Inc Milling, Turning, Bending, Welding · ISO 9001 | Pelzer, SC | MillingTurningBendingWelding | ISO 9001 |
| Southeastern Machining Milling, Turning, Welding · ISO 9001 | Worthington, OH | MillingTurningWelding | ISO 9001 |
| Spearpoint Manufacturing LLC Milling · ISO 9001, ITAR, CMMC | Traverse City, MI | Milling | ISO 9001, ITAR, CMMC |
| SPM Milling, Turning, Welding, EDM, Grinding, Finishing, Assembly · ISO 9001 | Portland, OR | MillingTurningWeldingEDMGrindingFinishingAssembly | ISO 9001 |
| Stanley Machining & Tool Corp Milling, Turning · ISO 9001 | Carpentersville, IL | MillingTurning | ISO 9001 |
| Starke Machine Co Milling, Turning · ISO 9001, AS9100, ITAR | Fort Worth, TX | MillingTurning | ISO 9001, AS9100, ITAR |
| Stephen J Hartman Milling, Turning, Welding, Grinding | Sykesville, MD | MillingTurningWeldingGrinding | - |
| Stork Precision Machining LLC Milling, Turning, Welding, EDM, Grinding · ISO 9001, CMMC | Washington, MO | MillingTurningWeldingEDMGrinding | ISO 9001, CMMC |
| Strohwig Industries, Inc Milling, Turning, Casting, EDM, Grinding, Finishing, Assembly · ISO 9001, ITAR, CMMC | Richfield, WI | MillingTurningCastingEDMGrindingFinishingAssembly | ISO 9001, ITAR, CMMC |
| Sulzer Machine & Manufacturing Inc Milling, Welding, Grinding · ISO 9001 | Mosinee, WI | MillingWeldingGrinding | ISO 9001 |
| Summit City Precision Machining LLC Milling, Turning, EDM · ISO 9001 | Fort Wayne, IN | MillingTurningEDM | ISO 9001 |
| Sunnycor Inc Milling, Turning, Grinding, Assembly · AS9100, ITAR | Torrington, CT | MillingTurningGrindingAssembly | AS9100, ITAR |
| Sunspot Solutions LLC Welding | Lyons, IN | Welding | - |
| Superior Jig Inc Milling, EDM · ISO 9001, ITAR | Anaheim, CA | MillingEDM | ISO 9001, ITAR |
| Superior Machining and Fabrication Inc Milling, Turning, Grinding, Assembly · ISO 9001, AS9100, ITAR | Muenster, TX | MillingTurningGrindingAssembly | ISO 9001, AS9100, ITAR |
| Superior Thread Rolling Co, LLC Milling, Turning, Grinding · ISO 9001, AS9100, NADCAP | Arleta, CA | MillingTurningGrinding | ISO 9001, AS9100, NADCAP |
| Support Equipment Inc Milling, Turning, Welding, EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR | Escondido, CA | MillingTurningWeldingEDMFinishingAssembly | ISO 9001, AS9100, ITAR |
| Supreme Gear Co Milling, Turning, Grinding · ISO 9001, NADCAP | Fraser, MI | MillingTurningGrinding | ISO 9001, NADCAP |
| Swissomation Inc Milling · ISO 9001, ITAR | Fredericksburg, TX | Milling | ISO 9001, ITAR |
| Sylhan LLC Milling, Turning, EDM · AS9100 | Edgewood, NY | MillingTurningEDM | AS9100 |
| T & D Specialties Milling, Turning, Swiss, Welding, Finishing · ISO 9001 | Oxford, MA | MillingTurningSwissWeldingFinishing | ISO 9001 |
| Tanksley Machine & Tool, Inc Milling, Turning, Laser, Welding, EDM, Grinding · AS9100 | Decatur, AL | MillingTurningLaserWeldingEDMGrinding | AS9100 |
| Target Laser & Machining, Inc Laser, Bending, Welding · ISO 9001 | Rockford, IL | LaserBendingWelding | ISO 9001 |
| Team Technologies Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100 | Albuquerque, NM | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, AS9100 |
| Tel-X Corporation Milling, Turning, Laser, Welding, Stamping, EDM, Finishing · ISO 9001, IATF 16949 | Garden City, MI | MillingTurningLaserWeldingStampingEDMFinishing | ISO 9001, IATF 16949 |
| Tessec LLC Milling, Welding, EDM, Grinding, Assembly · AS9100 | Dayton, OH | MillingWeldingEDMGrindingAssembly | AS9100 |
| The Charles Schillinger Co., Inc Turning, Welding, Stamping · ISO 9001 | Bensalem, PA | TurningWeldingStamping | ISO 9001 |
| The Inventors Shop, L.L.C Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping, Assembly · ISO 9001, ITAR | Cinnaminson, NJ | MillingTurningLaserWaterjetPunchingBendingWeldingStampingAssembly | ISO 9001, ITAR |
| Theonics Milling, Turning, Bending, Welding, EDM · AS9100, ITAR, ISO 13485 | Huntsville, AL | MillingTurningBendingWeldingEDM | AS9100, ITAR, ISO 13485 |
| Tobar Industries Milling, Turning, Bending, Welding | San Jose, CA | MillingTurningBendingWelding | - |
| TPR Systems Inc Milling, Turning, Waterjet, Bending, Welding, EDM · ISO 9001 | Milton, FL | MillingTurningWaterjetBendingWeldingEDM | ISO 9001 |