| Seattle Makers Laser, Welding, Metal AM | Seattle, WA | LaserWeldingMetal AM | - |
| Sharp Tooling Company Milling, Turning, Bending, Welding, Waterjet, EDM, Stamping, Metal AM | Buffalo, NY | MillingTurningBendingWeldingWaterjetEDMStampingMetal AM | - |
| Sonic Manufacturing Corporation Milling, Welding, EDM, Grinding, Finishing, Assembly · AS9100, NADCAP | Elk Grove Village, IL | MillingWeldingEDMGrindingFinishingAssembly | AS9100, NADCAP |
| Sse Steel Fabrication Milling, Turning, Bending, Welding | Saint Bernard, LA | MillingTurningBendingWelding | - |
| Sulzer Machine & Manufacturing Inc Milling, Welding, Grinding · ISO 9001 | Mosinee, WI | MillingWeldingGrinding | ISO 9001 |
| Superior Tooling Inc Milling, Turning, Swiss, Bending, Welding, Stamping, EDM, Grinding · ISO 9001 | Wapello, IA | MillingTurningSwissBendingWeldingStampingEDMGrinding | ISO 9001 |
| Sylvester Sheet Metal Bending, Welding | Manchester, NH | BendingWelding | - |
| Thermo-Craft Engineering Corp Milling, Turning, Waterjet, Punching, Bending, Welding, Grinding, Assembly | Lynn, MA | MillingTurningWaterjetPunchingBendingWeldingGrindingAssembly | - |
| Turntec Manufacturing Milling, Turning, Welding, Grinding | Mills, WY | MillingTurningWeldingGrinding | - |
| Vantage Manufacturing & Assembly LLC Milling, Turning, Laser, Welding, Assembly | Poughkeepsie, NY | MillingTurningLaserWeldingAssembly | - |
| Wayne Integrated Technologies Corp Milling, Bending, Welding, Assembly · ISO 9001, AS9100 | Edgewood, NY | MillingBendingWeldingAssembly | ISO 9001, AS9100 |