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).
Hand-drawn cross-section diagram of a mechanical part with annotations.
| Identifier | ExFiles\Box 95\4\ scan0026 | |
| Date | 25th June 1935 guessed | |
| .750 HONE 250 70° .200 | ||