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).
Recommendation for final tempering temperatures and duration.
| Identifier | ExFiles\Box 153\2\ scan0142 | |
| Date | 21th October 1936 | |
| -2- 21st, October 1936. We should definitely recommend that if a final tempering is found to be necessary, it should be carried out at a temperature of 125 to 130°C. for a longer period, say one to two hours, and that the latter temperature should in no case be exceeded. Yours faithfully, FOR ROLLS-ROYCE LIMITED. [Signature] TECHNICAL PRODUCTION ENGINEER. | ||