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).
Hardness test results for a 'Delco' double lever type damper shaft and inter-lever.
| Identifier | ExFiles\Box 151\2\ scan0308 | |
| Date | 9th June 1936 guessed | |
| 'DELCO' DOUBLE LEVER TYPE DAMPER, SHAFT HARDNESS TESTS, 700 BRINELL AT BOTTOM OF SERRATION, 571 BRINELL, 695 BRINELL, INTER - LEVER, 720 BRINELL, ROOT OF SERRATIONS, 724 TO 743 BRINELL, CORE, 285 BRINELL | ||