Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4830411 | Threaded joint for oil-well pipe | Eiji Tsuru, Shunji Nishi | 1989-05-16 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4830411 | Threaded joint for oil-well pipe | Eiji Tsuru, Shunji Nishi | 1989-05-16 |