| Number | Name | Date | Kind |
|---|---|---|---|
| 2031530 | Essick | Feb 1936 | |
| 2731543 | Appleton | Jan 1956 | |
| 3426818 | Derby | Feb 1969 | |
| 4396326 | McKinnie | Aug 1983 | |
| 5423646 | Gagnon | Jun 1995 |
| Entry |
|---|
| Industrial Fasteners and Closures Catalog IF93 Palnut Fasteners. |
| TRW Catalog PAL 91M Palnut Metric Fasteners. |