| Ravelin Inc Milling, Metal AM · ITAR | Cincinnati, OH | MillingMetal AM | ITAR |
| Raw Machining Co Milling | Buena Park, CA | Milling | - |
| RB Industrial Manufacturer LLC Milling, Swiss, Grinding | Racine, WI | MillingSwissGrinding | - |
| RDS Machine, LLC Milling, Turning, Finishing · ISO 9001, AS9100, ITAR, NADCAP | Newport, NH | MillingTurningFinishing | ISO 9001, AS9100, ITAR, NADCAP |
| Reardon Machine Co Inc Milling, Turning, Welding, Stamping, EDM, Grinding | Saint Joseph, MO | MillingTurningWeldingStampingEDMGrinding | - |
| RECR Milling, Waterjet, Bending, Welding | Dayton, OH | MillingWaterjetBendingWelding | - |
| Red Cliff Precision LLC Milling, Turning · ITAR | Spring, TX | MillingTurning | ITAR |
| Rensberger Technologies Milling, Turning, EDM · AS9100, ITAR, CMMC | Sioux Falls, SD | MillingTurningEDM | AS9100, ITAR, CMMC |
| Resivine LLC Milling, Turning, Waterjet, EDM, Grinding | Houston, TX | MillingTurningWaterjetEDMGrinding | - |
| RHS Precision LLC Milling, Turning, Finishing · ITAR | Edgewood, MD | MillingTurningFinishing | ITAR |
| Rice Precision Manufacturing Inc Milling, Turning, Swiss, Laser, Waterjet, Welding, Finishing, Assembly · ISO 9001, AS9100 | Baldwin City, KS | MillingTurningSwissLaserWaterjetWeldingFinishingAssembly | ISO 9001, AS9100 |
| Rig Machine Works LLC Milling, Turning, Bending, Welding, Grinding | Stevensville, MT | MillingTurningBendingWeldingGrinding | - |
| Rigid Concepts LLC Milling, Turning, Finishing · ISO 9001, ITAR | Van Alstyne, TX | MillingTurningFinishing | ISO 9001, ITAR |
| Rimeco Products Inc Milling, Turning, EDM · AS9100, ITAR, NADCAP | Willoughby, OH | MillingTurningEDM | AS9100, ITAR, NADCAP |
| Rincon Engineering Corporation Milling, Turning, Laser, Waterjet, Punching, Welding, Stamping, EDM, Finishing · ISO 9001, AS9100 | Carpinteria, CA | MillingTurningLaserWaterjetPunchingWeldingStampingEDMFinishing | ISO 9001, AS9100 |
| Riverside Machine and Engineering, Inc Milling · ISO 9001, AS9100, ISO 13485 | Eau Claire, WI | Milling | ISO 9001, AS9100, ISO 13485 |
| RJ Enterprises Milling, Turning, EDM · ISO 9001, AS9100, ITAR | Gardena, CA | MillingTurningEDM | ISO 9001, AS9100, ITAR |
| RMC Engine Rebuilding Equipment, Inc Milling | Saginaw, MI | Milling | - |
| RMT Corporation Milling, Turning, Welding, Grinding | Dayton, OH | MillingTurningWeldingGrinding | - |
| Robmar Precision, Inc Milling, Turning · ISO 9001, ITAR | Westland, MI | MillingTurning | ISO 9001, ITAR |
| Roush & Yates Racing Engines LLC Milling, Turning, Swiss, Waterjet, Finishing · AS9100, ITAR, NADCAP, ISO 13485 | Mooresville, NC | MillingTurningSwissWaterjetFinishing | AS9100, ITAR, NADCAP, ISO 13485 |
| Roysters Machine Shop LLC Milling, Turning, Waterjet, Welding, Stamping, EDM · ISO 9001 | Henderson, KY | MillingTurningWaterjetWeldingStampingEDM | ISO 9001 |
| Rozic Tool & Machine LLC Milling, Turning, EDM · ISO 9001 | Euclid, OH | MillingTurningEDM | ISO 9001 |
| S & H Machine Co Inc Milling, Turning | Buffalo, NY | MillingTurning | - |
| S & H Machine, Inc Milling, Turning, Assembly · ISO 9001, AS9100, ITAR | Burbank, CA | MillingTurningAssembly | ISO 9001, AS9100, ITAR |
| S & S Tool & Machine Co Milling, Turning, Welding, EDM, Grinding · ISO 9001, AS9100, ITAR | Louisville, KY | MillingTurningWeldingEDMGrinding | ISO 9001, AS9100, ITAR |
| S&W Precision Machining LLC Milling, Turning · ISO 9001, AS9100, ITAR, CMMC | Commerce City, CO | MillingTurning | ISO 9001, AS9100, ITAR, CMMC |
| Saliga Machine Co Inc Milling, Bending, Welding, Stamping, EDM, Finishing · ISO 9001 | Hudson, MA | MillingBendingWeldingStampingEDMFinishing | ISO 9001 |
| San Diego Precision Machining Inc Milling, Turning, Welding, EDM · ISO 9001, AS9100 | San Diego, CA | MillingTurningWeldingEDM | ISO 9001, AS9100 |
| Savage Machining Inc Milling, Turning, EDM, Finishing, Assembly · ISO 9001 | Simi Valley, CA | MillingTurningEDMFinishingAssembly | ISO 9001 |
| Schmid Tool & Engineering Corp Milling, Turning, Swiss, Stamping, Grinding, Finishing, Assembly · ISO 9001, ITAR | Villa Park, IL | MillingTurningSwissStampingGrindingFinishingAssembly | ISO 9001, ITAR |
| Schmiede Corporation Milling, Turning, Welding, EDM, Grinding, Assembly · ISO 9001 | Tullahoma, TN | MillingTurningWeldingEDMGrindingAssembly | ISO 9001 |
| Schneiders Manufacturing Inc Milling, Turning, Swiss, EDM, Grinding · ISO 9001, AS9100, ITAR | Sun Valley, CA | MillingTurningSwissEDMGrinding | ISO 9001, AS9100, ITAR |
| Scull Manufacturing, LLC Milling, Turning, Grinding | Olean, NY | MillingTurningGrinding | - |
| Selectwo Machine Company, Inc Milling, Turning, Welding, Stamping, EDM · ISO 9001, AS9100 | Longwood, FL | MillingTurningWeldingStampingEDM | ISO 9001, AS9100 |
| Selway Machine Tool Co Inc Milling, Turning, Metal AM | Salt Lake City, UT | MillingTurningMetal AM | - |
| Semco Machine Corporation Milling, Turning | Plainville, MA | MillingTurning | - |
| SendCutSend Milling, Bending, Laser, Welding, Waterjet | Reno, NV | MillingBendingLaserWeldingWaterjet | - |
| Seneca Manufacturing LLC Milling, Turning, Welding | Tiffin, OH | MillingTurningWelding | - |
| Service Metal Fabricators Inc Milling, Punching, Bending, Welding, Stamping, Grinding, Finishing, Assembly | Williamsburg, VA | MillingPunchingBendingWeldingStampingGrindingFinishingAssembly | - |
| Seven Star Marine Inc Milling, Turning, Waterjet, Bending, Welding, Finishing · ISO 9001 | Newport, RI | MillingTurningWaterjetBendingWeldingFinishing | ISO 9001 |
| Shackelford Machine Inc Milling, Turning, Assembly · ISO 9001, AS9100, ITAR | Clearwater, KS | MillingTurningAssembly | ISO 9001, AS9100, ITAR |
| Shalo Tek Inc Milling | Rincon, GA | Milling | - |
| Shamrock Precision Milling, Turning, Bending · ISO 9001, AS9100 | Dallas, TX | MillingTurningBending | ISO 9001, AS9100 |
| Shape Shifters Inc Milling, Waterjet, Bending, Welding, Stamping, Finishing | Bloomfield, IN | MillingWaterjetBendingWeldingStampingFinishing | - |
| 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 |
| Sicom Industries USA LLC Milling, Turning, Waterjet · ISO 9001, AS9100, CMMC | Stanwood, WA | MillingTurningWaterjet | ISO 9001, AS9100, CMMC |
| Sinclair and Sons Custom Welding and Machining Service Inc Milling, Turning, Waterjet, Welding, Assembly · ISO 9001, AS9100, NADCAP | Wichita, KS | MillingTurningWaterjetWeldingAssembly | ISO 9001, AS9100, NADCAP |
| SKP Machine Enterprises LLC Milling, Turning | Monticello, KY | MillingTurning | - |
| Smi Metal Precision LLC Milling | Houston, TX | Milling | - |