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).
Test report on the breakdown voltage of a 'Tufnol' sheet sample.
| Identifier | ExFiles\Box 61\1\ scan0145 | |
| Date | 4th November 1930 | |
| X6110.. EFC. 4.11.30. The breakdown volts of the sample of sheet "Tufnol" .065" thick was 24,200 volts (peak). This works out at 373 volts per mil. HEW. | ||