| S & S Machine Inc Milling, Turning, Waterjet, Punching, Bending, Welding, Assembly · ISO 9001, AS9100, ITAR | Irving, TX | MillingTurningWaterjetPunchingBendingWeldingAssembly | ISO 9001, AS9100, ITAR |
| Sales & Engineering Inc Milling, Turning, Bending, Welding, Stamping | Livonia, MI | MillingTurningBendingWeldingStamping | - |
| San Diego Precision Machining Inc Milling, Turning, Welding, EDM · ISO 9001, AS9100 | San Diego, CA | MillingTurningWeldingEDM | ISO 9001, AS9100 |
| Sawyer Manufacturing Company Turning, Welding, Finishing | Tulsa, OK | TurningWeldingFinishing | - |
| Seneca Manufacturing LLC Milling, Turning, Welding | Tiffin, OH | MillingTurningWelding | - |
| Seven Star Marine Inc Milling, Turning, Waterjet, Bending, Welding, Finishing · ISO 9001 | Newport, RI | MillingTurningWaterjetBendingWeldingFinishing | ISO 9001 |
| SFC Tec, Inc Milling, Turning, Laser, Bending, Welding | Delta, UT | MillingTurningLaserBendingWelding | - |
| Shamrock Machining Inc Milling, Turning, Bending, Laser, Welding · ISO 9001 | Spokane Valley, WA | MillingTurningBendingLaserWelding | ISO 9001 |
| Shaw Industries Co. LLC Milling, Turning, Welding, EDM · ISO 9001, ITAR | Franklin, PA | MillingTurningWeldingEDM | ISO 9001, ITAR |
| Shoemaker Mfg Solutions Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Stamping, Grinding · ISO 9001, AS9100, ITAR, CMMC | Souderton, PA | MillingTurningLaserWaterjetPunchingBendingWeldingStampingGrinding | ISO 9001, AS9100, ITAR, CMMC |
| Silicon Valley Precision Inc Milling, Turning, Welding, Casting, Grinding, Finishing · ITAR | Livermore, CA | MillingTurningWeldingCastingGrindingFinishing | ITAR |
| Skytop Machine and Tool, Inc Milling, Turning, Waterjet, Welding, Grinding | Port Matilda, PA | MillingTurningWaterjetWeldingGrinding | - |
| Slim Haney Machining Inc Milling, Turning, Welding | Tulsa, OK | MillingTurningWelding | - |
| SMT Machine & Tool Milling, Turning, Welding, Casting | Green Bay, WI | MillingTurningWeldingCasting | - |
| Smyth County Machine & Fabrication LLC Turning, Welding | Glade Spring, VA | TurningWelding | - |
| Soflo Machining Milling, Turning, Laser, Waterjet, Welding, Grinding, Finishing · ISO 9001, AS9100 | Coral Springs, FL | MillingTurningLaserWaterjetWeldingGrindingFinishing | ISO 9001, AS9100 |
| Solvers Manufacturing Turning, Bending, Welding | Springfield, NE | TurningBendingWelding | - |
| Soteria LLC Milling, Turning, Welding, Grinding, Finishing | Anniston, AL | MillingTurningWeldingGrindingFinishing | - |
| Southeastern Machine Works, Inc Milling, Turning, Welding | Live Oak, FL | MillingTurningWelding | - |
| Southern Ohio Manufacturing Milling, Turning, Laser, Bending, Welding, Grinding, Finishing | Amelia, OH | MillingTurningLaserBendingWeldingGrindingFinishing | - |
| Southwest Industrial Sales LLC Milling, Turning, Swiss, Bending, Welding, EDM, Assembly · ISO 9001, AS9100, ITAR, ISO 13485, CMMC | Chandler, AZ | MillingTurningSwissBendingWeldingEDMAssembly | ISO 9001, AS9100, ITAR, ISO 13485, CMMC |
| Southwest Precision Machining, L.L.C Milling, Turning, Swiss, Welding, Finishing | Tucson, AZ | MillingTurningSwissWeldingFinishing | - |
| Spartan Machine LLC Milling, Turning | Spring, TX | MillingTurning | - |
| Sparton Technology Corp Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100 | Hudson, NH | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100 |
| 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 Deal Machining Inc Milling, Turning, Laser, Bending, Welding, Grinding, Finishing, Assembly | Marathon, NY | MillingTurningLaserBendingWeldingGrindingFinishingAssembly | - |
| SRS Fabrication Inc. Milling, Turning, Bending, Welding, Waterjet | North Las Vegas, NV | MillingTurningBendingWeldingWaterjet | - |
| Stampede Die Corp Milling, Turning, Waterjet, Welding, Casting, EDM | Wayland, MI | MillingTurningWaterjetWeldingCastingEDM | - |
| 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 |
| Stark Industrial, LLC Milling, Turning, Swiss, Welding, EDM, Grinding · ISO 9001 | North Canton, OH | MillingTurningSwissWeldingEDMGrinding | ISO 9001 |
| Steer Machine Tool and Die Corporation Milling, Turning, Welding, Grinding | Honesdale, PA | MillingTurningWeldingGrinding | - |
| Stephens Precision, Inc Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Bradford, VT | MillingTurningWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Sterling Machine Technologies Turning, Bending, Welding | Palmyra, PA | TurningBendingWelding | - |
| Steward Machine Co., Inc Turning, Welding, Assembly | Birmingham, AL | TurningWeldingAssembly | - |
| Stockton Tri-Industries, LLC Milling, Turning, Waterjet, Bending, Welding, Assembly | Stockton, CA | MillingTurningWaterjetBendingWeldingAssembly | - |
| Strickland Industries Milling, Turning, Laser, Bending, Welding, Assembly | Mansfield, TX | MillingTurningLaserBendingWeldingAssembly | - |
| Strickland Machine Co LLC Milling, Turning, Welding, Stamping, Grinding, Finishing, Assembly | North Chesterfield, VA | MillingTurningWeldingStampingGrindingFinishingAssembly | - |
| Subtract LLC Milling, Turning, Swiss, Laser, Waterjet, Welding, EDM, Finishing | Muncie, IN | MillingTurningSwissLaserWaterjetWeldingEDMFinishing | - |
| 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 | - |
| Superior Machine & Tool Milling, Turning, Welding · ISO 9001 | Fort Wayne, IN | MillingTurningWelding | ISO 9001 |
| Superior Technology Inc Milling, Turning, Swiss, Welding, Grinding, Finishing, Assembly · ISO 9001 | Rochester, NY | MillingTurningSwissWeldingGrindingFinishingAssembly | ISO 9001 |
| Superior Tooling Inc Milling, Turning, Swiss, Bending, Welding, Stamping, EDM, Grinding · ISO 9001 | Wapello, IA | MillingTurningSwissBendingWeldingStampingEDMGrinding | ISO 9001 |
| Support Equipment Inc Milling, Turning, Welding, EDM, Finishing, Assembly · ISO 9001, AS9100, ITAR | Escondido, CA | MillingTurningWeldingEDMFinishingAssembly | ISO 9001, AS9100, ITAR |
| Swan Island Sheet Metal Works Turning, Bending, Laser, Welding | Portland, OR | TurningBendingLaserWelding | - |
| Swiss Technologies Inc. Milling, Turning, Welding, Stamping · ISO 9001 | Knoxville, TN | MillingTurningWeldingStamping | ISO 9001 |
| Swiss Wire EDM Milling, Turning, Welding, EDM · ISO 9001, ITAR, NADCAP | Costa Mesa, CA | MillingTurningWeldingEDM | ISO 9001, ITAR, NADCAP |