Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4823847 | Multi-layer helical seam steel pipe | Heinz Grosse, Friedrich-Otto Koch, Werner Wennemann | 1989-04-25 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4823847 | Multi-layer helical seam steel pipe | Heinz Grosse, Friedrich-Otto Koch, Werner Wennemann | 1989-04-25 |