Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6220305 | Coal tar enamel coated steel pipe and process for same | John R. Johnson, William R. Roder | 2001-04-24 |
| 5713393 | Coal tar enamel coated steel pipe and process for same | John R. Johnson, William R. Roder | 1998-02-03 |
| 5567480 | Coal tar enamel coated steel pipe and process for producing same | John R. Johnson, William R. Roder | 1996-10-22 |