| Seattle Makers Laser, Welding, Metal AM | Seattle, WA | LaserWeldingMetal AM | - |
| Serrmi Products LLC Milling, Turning, Laser, Punching, Bending, Finishing | Pittsburg, KS | MillingTurningLaserPunchingBendingFinishing | - |
| Sharp Tooling Company Milling, Turning, Bending, Welding, Waterjet, EDM, Stamping, Metal AM | Buffalo, NY | MillingTurningBendingWeldingWaterjetEDMStampingMetal AM | - |
| Sifco Industries Inc Forging, Finishing, Assembly · ISO 9001, NADCAP | Cleveland, OH | ForgingFinishingAssembly | ISO 9001, NADCAP |
| SKP Machine Enterprises LLC Milling, Turning | Monticello, KY | MillingTurning | - |
| Slag Factory Milling, Laser, Welding | Oroville, CA | MillingLaserWelding | - |
| Sonic Manufacturing Corporation Milling, Welding, EDM, Grinding, Finishing, Assembly · AS9100, NADCAP | Elk Grove Village, IL | MillingWeldingEDMGrindingFinishingAssembly | AS9100, NADCAP |
| Southwest Greene International Inc Milling, Turning, Stamping, Metal AM, EDM | Oceanside, CA | MillingTurningStampingMetal AMEDM | - |
| Specialty Roller and Machine Inc Milling, Turning, Grinding | Berwick, PA | MillingTurningGrinding | - |
| Sse Steel Fabrication Milling, Turning, Bending, Welding | Saint Bernard, LA | MillingTurningBendingWelding | - |
| Sterling Edge Industrial Cutting, LLC Laser, Waterjet | Denver, CO | LaserWaterjet | - |
| Stone Machine Co. Inc Milling, Turning, Grinding, Finishing | Chester, NH | MillingTurningGrindingFinishing | - |
| Strom Manufacturing, LLC Milling, Turning, Finishing, Assembly · ISO 9001 | North Plains, OR | MillingTurningFinishingAssembly | ISO 9001 |
| 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 | - |
| Systems Powered Manufacturing, LLC Grinding, Finishing, Assembly | Saint Charles, IL | GrindingFinishingAssembly | - |
| Tarman Machine Company, Inc. Welding | Canal Winchester, OH | Welding | - |
| Texarkana Machine Inc Milling, Turning, Waterjet, Welding, Grinding, Finishing | Texarkana, TX | MillingTurningWaterjetWeldingGrindingFinishing | - |
| TM Industries Inc Milling, Welding | Santa Clara, CA | MillingWelding | - |
| Treske Precision Machining Inc Milling, Assembly | Sherwood, OR | MillingAssembly | - |
| Tri-State Tool Grinding Incorporated Milling, Grinding · ISO 9001 | Cincinnati, OH | MillingGrinding | ISO 9001 |
| Trust Manufacturing LLC Milling, Turning, Waterjet, Bending, Forging, EDM, Grinding, Finishing | Euclid, OH | MillingTurningWaterjetBendingForgingEDMGrindingFinishing | - |
| Turntec Manufacturing Milling, Turning, Welding, Grinding | Mills, WY | MillingTurningWeldingGrinding | - |
| U.m.c., Inc Milling, Turning, Welding, Stamping, EDM, Grinding, Finishing · ISO 9001, ITAR, ISO 13485 | Monticello, MN | MillingTurningWeldingStampingEDMGrindingFinishing | ISO 9001, ITAR, ISO 13485 |
| Ultimate Manufacturing, Inc Milling, Turning, Grinding | Oakland Park, FL | MillingTurningGrinding | - |
| Ultra-Tech Aerospace, Inc Milling, Welding, EDM, Grinding, Assembly · ISO 9001, AS9100, NADCAP | Kansas City, KS | MillingWeldingEDMGrindingAssembly | ISO 9001, AS9100, NADCAP |
| Ultrastratech LLC Milling, Turning, Bending, Stamping · CMMC | Tucson, AZ | MillingTurningBendingStamping | CMMC |
| Universal Machine & Tool, Inc Milling, Turning, Laser, Waterjet, Bending, Welding, EDM, Grinding | Kingsport, TN | MillingTurningLaserWaterjetBendingWeldingEDMGrinding | - |
| 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 |
| Whi Global, LLC Milling, Turning, Forging, Assembly · ISO 9001, ITAR, NADCAP | Tulsa, OK | MillingTurningForgingAssembly | ISO 9001, ITAR, NADCAP |
| Zakobe LLC Stamping, EDM · ISO 9001, AS9100, ISO 13485 | Bovey, MN | StampingEDM | ISO 9001, AS9100, ISO 13485 |