| Slagel Manufacturing, Inc Bending, Welding, Finishing · ISO 9001 | Forrest, IL | BendingWeldingFinishing | ISO 9001 |
| Smith Metal, LLC Milling, Turning, Swiss, Laser, Waterjet, Bending, Welding, EDM, Grinding, Finishing · ISO 9001 | Augusta, MI | MillingTurningSwissLaserWaterjetBendingWeldingEDMGrindingFinishing | ISO 9001 |
| Solvers Manufacturing Turning, Bending, Welding | Springfield, NE | TurningBendingWelding | - |
| Sound Manufacturing, Inc Milling, Laser, Punching, Bending, Welding, Assembly · ISO 9001 | Old Saybrook, CT | MillingLaserPunchingBendingWeldingAssembly | ISO 9001 |
| South Austin Metals Bending, Welding | Austin, TX | BendingWelding | - |
| South Eastern Machining Inc Milling, Turning, Bending, Welding · ISO 9001 | Pelzer, SC | MillingTurningBendingWelding | ISO 9001 |
| 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 |
| Sparton Technology Corp Milling, Turning, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, AS9100 | Hudson, NH | MillingTurningLaserPunchingBendingWeldingFinishingAssembly | ISO 9001, AS9100 |
| Specialty Engineering Inc Laser, Punching, Bending, Welding, Assembly · ISO 9001 | Saint Paul, MN | LaserPunchingBendingWeldingAssembly | ISO 9001 |
| Specialty Machine Milling, Turning, Swiss, Laser, Bending, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, ITAR | Lago Vista, TX | MillingTurningSwissLaserBendingWeldingEDMGrindingAssembly | ISO 9001, AS9100, ITAR |
| Specialty Metal Fabricators Bending, Welding | Portland, OR | BendingWelding | - |
| Specialty Steel Supply Co., Inc Punching, Bending, Welding | Fairless Hills, PA | PunchingBendingWelding | - |
| Specialty Tool & Die Company Inc Milling, Turning, Bending, Welding, Stamping, Grinding, Assembly | Kokomo, IN | MillingTurningBendingWeldingStampingGrindingAssembly | - |
| Speed Fabrication LLC Laser, Bending, Welding, Finishing | Perryville, MO | LaserBendingWeldingFinishing | - |
| Spokane Tin & Sheet Iron Works, Inc. Bending, Welding | Spokane, WA | BendingWelding | - |
| Spring Creek Machining, Inc Milling, Turning, Waterjet, Bending, Welding, EDM, Grinding, Finishing | Lowell, AR | MillingTurningWaterjetBendingWeldingEDMGrindingFinishing | - |
| Spring Grove Sheet Metal Bending, Laser, Welding | Cincinnati, OH | BendingLaserWelding | - |
| Springs Fabrication, LLC Bending, Welding, Waterjet · ISO 9001, ITAR | Colorado Springs, CO | BendingWeldingWaterjet | ISO 9001, ITAR |
| 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 | - |
| Sse Steel Fabrication Milling, Turning, Bending, Welding | Saint Bernard, LA | MillingTurningBendingWelding | - |
| Steel House Bending, Welding | Indianapolis, IN | BendingWelding | - |
| Steel Plate Fabricators Milling, Turning, Bending, Laser, Welding, Waterjet, Metal AM | Knoxville, TN | MillingTurningBendingLaserWeldingWaterjetMetal AM | - |
| Steel Valley Fabricators, LLC Milling, Bending, Welding | Braddock, PA | MillingBendingWelding | - |
| Steel Werx Bending, Welding | Santa Clara, CA | BendingWelding | - |
| Steel-Craft Corp. of Hartford Milling, Laser, Punching, Bending, Welding, Stamping, Finishing | Hartford, WI | MillingLaserPunchingBendingWeldingStampingFinishing | - |
| Steeltron Metal Works Bending, Welding | San Antonio, TX | BendingWelding | - |
| Stehl Corp Punching, Bending, Welding | Phoenix, AZ | PunchingBendingWelding | - |
| Stellar Industries LLC Laser, Bending, Welding, Stamping, Finishing · ISO 9001 | Nappanee, IN | LaserBendingWeldingStampingFinishing | ISO 9001 |
| Sterling Machine Technologies Turning, Bending, Welding | Palmyra, PA | TurningBendingWelding | - |
| Still Waters Metal Fab LLC Bending, Welding | Spokane Valley, WA | BendingWelding | - |
| Stockton Tri-Industries, LLC Milling, Turning, Waterjet, Bending, Welding, Assembly | Stockton, CA | MillingTurningWaterjetBendingWeldingAssembly | - |
| Strickland Industries Milling, Turning, Laser, Bending, Welding, Assembly | Mansfield, TX | MillingTurningLaserBendingWeldingAssembly | - |
| Striking Precision Welding & Fabrication Milling, Bending, Welding · ISO 9001, ITAR | Cedar Park, TX | MillingBendingWelding | ISO 9001, ITAR |
| Strong Forge & Fabrication, LLC Milling, Bending, Welding, Finishing | Batavia, NY | MillingBendingWeldingFinishing | - |
| Structural Steel & Plate Fab Bending, Welding | North Salt Lake, UT | BendingWelding | - |
| Summit Products Inc Milling, Bending, Welding, Finishing | Altoona, IA | MillingBendingWeldingFinishing | - |
| Superior Process Solutions Milling, Turning, Bending, Laser, Welding, Metal AM | Springfield, MO | MillingTurningBendingLaserWeldingMetal AM | - |
| Superior Tooling Inc Milling, Turning, Swiss, Bending, Welding, Stamping, EDM, Grinding · ISO 9001 | Wapello, IA | MillingTurningSwissBendingWeldingStampingEDMGrinding | ISO 9001 |
| Surfix Inc Milling, Bending, Welding | Palm Bay, FL | MillingBendingWelding | - |
| Susquehanna Metal Work, LLC Milling, Bending, Welding, Stamping | Columbia, PA | MillingBendingWeldingStamping | - |
| Swan Island Sheet Metal Works Turning, Bending, Laser, Welding | Portland, OR | TurningBendingLaserWelding | - |
| 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 |
| Sylvester Sheet Metal Bending, Welding | Manchester, NH | BendingWelding | - |
| T & T Metals Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001 | Covina, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001 |
| Tabet Manufacturing Co Inc Milling, Turning, Laser, Waterjet, Punching, Bending, Welding, Finishing, Assembly · ISO 9001, ITAR | Norfolk, VA | MillingTurningLaserWaterjetPunchingBendingWeldingFinishingAssembly | ISO 9001, ITAR |
| Target Laser & Machining, Inc Laser, Bending, Welding · ISO 9001 | Rockford, IL | LaserBendingWelding | ISO 9001 |
| Tec Inc Milling, Turning, Swiss, Laser, Punching, Bending, Welding, Finishing, Assembly · ISO 9001 | Frederick, MD | MillingTurningSwissLaserPunchingBendingWeldingFinishingAssembly | ISO 9001 |