| 1 | STWX | H. Emerson Thomas, Trustee | added 4/1963; eliminated 1/1964 | | NAKINA |
| 2 | STWX | Shippers' Car Line Division of ACF Industries, Inc. | added 1/1964; 7/1965; eliminated 4/1966 | | NAKINA |
| 3 | STWX | Struthers Wells Corp. | added 10/1979; 1/1980; eliminated 4/1989; 1/1994 (not listed) | | NAKINA |
| 4 | STWX | Steelwheels, LLC | 7/2005 (not listed); added 10/2005; eliminated 10/2006 | | NAKINA |
| 5 | STWX | Shippers' Car Line Division of ACF Industries, Inc. | 7/65; eliminated 4/66 | | NRHS |
| 6 | STWX | Struthers Wells Corp. | 1/80; eliminated 4/89; 1/94 | | NRHS |
| 7 | STWX | *SHIPPERS' CAR LINE DIV. OF ACF INDUSTRIES, INC. | | | PWRC |
| 8 | STWX | *STRUTHERS WELLS CORP. | | | PWRC |
| 9 | STWX | +STEELWHEELS, LLC | | | PWRC |
| 10 | STWX | Struthers Wells Corporation | | | RSRV |
| 11 | STWX | STEELWHEELS LLC | | | SCAC4 |