From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Note discussing the compromise between a brass thread and a wholly lead insert.
| Identifier | ExFiles\Box 168b\3\ img265 | |
| Date | 10th February 1930 guessed | |
| II J.D.54. brass thread. The only alternative is to have a wholly lead insert, but this would not be satisfactory because the lead thread would soon be stripped. Hence we have to make the best compromise. F.J. | ||