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).
Achieving magnet permanency and comparing steel composition and hardness against a Bosch equivalent.
| Identifier | ExFiles\Box 4\5\ 05-page052 | |
| Date | 20th May 1918 guessed | |
| To Na.{Mr Nadin} from R.{Sir Henry Royce} 2. R6/IB21114. greatest permanency would undoubtedly require the larger current in the coils, but care should be taken that the time was equal and the conditions also, that is, avoid any shock or hammering of the magnet whilst under the influence of the demagnetising current, so that we can now compare them by such processes as has been suggested, amongst which are the (1) boiling in water and this (2) demagnetising influence herein suggested. It is of the utmost importance that the permanency should be good. At the same time we may be able to see some reason for the advantage we have obtained over the Bosch, when we see the report of analysis of the steel we have found so satisfactory. For instance, it may be higher in carbon, tungsten or chromium, and it would be as well to take the scleroscope hardness in each case. R.{Sir Henry Royce} | ||