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).
Letter detailing the correct procedure for blocking high-pressure drillings using threaded plugs.
| Identifier | ExFiles\Box 152\1\ scan0244 | |
| Date | 25th January 1937 guessed | |
| -2- We always block drillings in high pressure passages by screwing in a plug of similar material to the casing right to the end of the tapping in the hole. Your plugs appear not to be threaded. Yours sincerely, | ||