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).
Specifications for timing gears, including steel composition, hardening processes, and collaboration with Ford's.
| Identifier | ExFiles\Box 126\3\ scan0056 | |
| Date | 17th December 1936 | |
| -2- Rm{William Robotham - Chief Engineer}7/R.17.12.36. One set of timing gears should be ground before hardening, the other set shaved. Ford's have agreed to do all the necessary cyanide hardening, etc., so that the experiment will not get confused by our lack of technique in this matter. It is important to specify that the steel grain structure must lie between 4 to 5 on the McQuaid scale. The specification of the steel which should be given to Messrs. Samuel Fox is "Ford AAAH" standard:- Carbon .......... .35-.38 Manganese ....... .65-.80 Chromium ........ .90-1.10 Silicon .......... .10-.20 Phosphorus ...... .03 Max. Sulphur ......... .04 Max. The gears should be very carefully checked up for tooth form and pitch, etc. before being sent to Ford's. Rm.{William Robotham - Chief Engineer} | ||