| South Bend Form Tool Co Milling, Turning, EDM | South Bend, IN | MillingTurningEDM | - |
| South Austin Metals Bending, Welding | Austin, TX | BendingWelding | - |
| South Central Manufacturing Corp Milling, Turning, Welding, Grinding | Summersville, MO | MillingTurningWeldingGrinding | - |
| Southeastern Machine Works, Inc Milling, Turning, Welding | Live Oak, FL | MillingTurningWelding | - |
| Southern Metal Fabricators, Inc Welding, Casting | Albertville, AL | WeldingCasting | - |
| Southern Ohio Manufacturing Milling, Turning, Laser, Bending, Welding, Grinding, Finishing | Amelia, OH | MillingTurningLaserBendingWeldingGrindingFinishing | - |
| Southern Precision, Inc Milling, Turning, Stamping | Saint Rose, LA | MillingTurningStamping | - |
| Southern Rut Performance LLC Welding | Dahlonega, GA | Welding | - |
| Southern Precision Machining Milling, Turning, Grinding, Finishing · ISO 9001, AS9100, ITAR | Shelbyville, TN | MillingTurningGrindingFinishing | ISO 9001, AS9100, ITAR |
| 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 |
| Gulf South Machine Inc Milling, Turning | Ponchatoula, LA | MillingTurning | - |
| 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 |
| Southwest Greene International Inc Milling, Turning, Stamping, Metal AM, EDM | Oceanside, CA | MillingTurningStampingMetal AMEDM | - |
| Southwest Precision Machining, L.L.C Milling, Turning, Swiss, Welding, Finishing | Tucson, AZ | MillingTurningSwissWeldingFinishing | - |
| Southwest Waterjet and Laser Milling, Laser, Waterjet, Bending | Phoenix, AZ | MillingLaserWaterjetBending | - |
| Sugar River Machine Inc Milling, Turning, Welding, Grinding, Finishing, Assembly | South Beloit, IL | MillingTurningWeldingGrindingFinishingAssembly | - |
| A & A Co Inc Milling, Welding, Grinding | South Plainfield, NJ | MillingWeldingGrinding | - |
| Bertrand Products, Inc Milling, Turning, Grinding, Finishing · ISO 9001 | South Bend, IN | MillingTurningGrindingFinishing | ISO 9001 |
| Buddy Bar Casting, LLC Milling, Casting | South Gate, CA | MillingCasting | - |
| C.V. Industries Milling, Turning, EDM | Southington, CT | MillingTurningEDM | - |
| Clinkenbeard & Associates Inc Milling, Casting, Assembly · AS9100, ITAR | South Beloit, IL | MillingCastingAssembly | AS9100, ITAR |
| Dynamic Machining Inc Milling, Turning | South Salt Lake, UT | MillingTurning | - |
| Engel Mfg. Milling · ISO 9001, AS9100 | South Bend, IN | Milling | ISO 9001, AS9100 |
| F.B.F., Inc Laser, Punching, Bending, Welding, Stamping, Assembly · ISO 9001 | Southampton, PA | LaserPunchingBendingWeldingStampingAssembly | ISO 9001 |
| Forma Machine, LLC Milling, Casting · AS9100 | South Pittsburg, TN | MillingCasting | AS9100 |
| IFT Worldwide Milling, Stamping, Finishing | South Bend, IN | MillingStampingFinishing | - |
| Kris Dee and Associates, Inc Milling, Casting · ISO 9001, AS9100, ITAR | South Elgin, IL | MillingCasting | ISO 9001, AS9100, ITAR |
| Machine Tool Technology LLC Milling, EDM | South Chesterfield, VA | MillingEDM | - |
| Mathias Die Co Inc Milling, Laser, Waterjet, Stamping, EDM · ISO 9001, ITAR | South Saint Paul, MN | MillingLaserWaterjetStampingEDM | ISO 9001, ITAR |
| Metalogic Industries LLC Milling, Turning, Swiss, Laser, Welding, EDM, Grinding | Southbridge, MA | MillingTurningSwissLaserWeldingEDMGrinding | - |
| Micro Precision, LLC Milling · ISO 9001 | South Windham, CT | Milling | ISO 9001 |
| Midway Machine & Instrument Company Inc Milling, Turning, EDM, Finishing · ISO 9001 | South Houston, TX | MillingTurningEDMFinishing | ISO 9001 |
| Skillcraft Machine Tool Co Inc Milling, Turning, Welding | South Windsor, CT | MillingTurningWelding | - |
| The Bennu Group Inc Milling, Turning, Waterjet, Welding, Finishing · ISO 9001 | South Holland, IL | MillingTurningWaterjetWeldingFinishing | ISO 9001 |
| Whalley Precision Inc Milling, Turning, Welding, Grinding, Finishing, Assembly · ISO 9001, ITAR, CMMC | Southwick, MA | MillingTurningWeldingGrindingFinishingAssembly | ISO 9001, ITAR, CMMC |
| Whip City Tool & Die Corporation Stamping | Southwick, MA | Stamping | - |
| Wieland Techni-Cast Milling, Casting | South Gate, CA | MillingCasting | - |
| Dms-South/bailey Tool LLC Milling, Turning, Welding, Stamping, EDM | Lancaster, TX | MillingTurningWeldingStampingEDM | - |
| A.m.i. Engineering Co LLC Milling, Turning, Finishing · ISO 9001, ITAR | Santa Ana, CA | MillingTurningFinishing | ISO 9001, ITAR |
| Accu Die & Mold, Inc Milling, Turning, Welding, Casting, EDM | Stevensville, MI | MillingTurningWeldingCastingEDM | - |
| Advanced Metal Manufacturing Inc Milling, Laser, Punching, Bending, Welding, Finishing · ISO 9001, AS9100 | Simi Valley, CA | MillingLaserPunchingBendingWeldingFinishing | ISO 9001, AS9100 |
| Advanced Precision Machining, LLC Milling, Turning, Laser, Waterjet, EDM, Assembly · AS9100, ITAR, CMMC | Costa Mesa, CA | MillingTurningLaserWaterjetEDMAssembly | AS9100, ITAR, CMMC |
| Aerotar Inc Milling, Welding, Grinding · ISO 9001 | Opa Locka, FL | MillingWeldingGrinding | ISO 9001 |
| Anaheim Precision Milling, Turning, Bending, Laser, Welding, Waterjet · ISO 9001, AS9100, NADCAP | Orange, CA | MillingTurningBendingLaserWeldingWaterjet | ISO 9001, AS9100, NADCAP |
| Apex Design Technology of Alabama LLC Milling, Turning, Bending, Welding, Assembly · ISO 9001 | Decatur, AL | MillingTurningBendingWeldingAssembly | ISO 9001 |
| ARC Fabricators Bending, Welding | Sioux Falls, SD | BendingWelding | - |
| BK Customs Bending, Laser, Welding, Waterjet | Riverside, CA | BendingLaserWeldingWaterjet | - |
| Campbell Engineering Milling, Welding, EDM, Finishing, Assembly · ISO 9001, ITAR | Lake Forest, CA | MillingWeldingEDMFinishingAssembly | ISO 9001, ITAR |
| Carollo Metal Works Welding | Chalmette, LA | Welding | - |