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).
Outlining an experiment to test the claims of cyanide hardening for gears.
| Identifier | ExFiles\Box 126\3\ scan0055 | |
| Date | 17th December 1936 | |
| 1065 HPS.{Horace Percy Smith - Experimental Factory Mgr} from Rm.{William Robotham - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} c. to RHC.{R. H. Coverley - Production Engineer} Rm{William Robotham - Chief Engineer}7/R.17.12.36. CYANIDE HARDENING OF GEARS. The object of this experiment is to ascertain whether the claims for this steel can be substantiated. Cyanide hardening is alleged to reduce distortion considerably, to be applicable to a steel which is very easy to machine, as before hardening it is only 220 Brinell, and in the final state to give a stronger gear on small teeth owing to the small depth of case which is only 005. It is quite possible that for our work this steel may be quite useless for gearbox gears, but we believe it should have an application for timing gears. We think, however, that it is worth trying for gearbox gears in view of the fact that we are at present being pushed off hardened splines due to distortion. The usual objection to this steel is that the core is too brittle. The Ford Co. maintain that they have overcome this difficulty by paying attention to the grain size of the steel, also reducing the Brinell of the core, which on the steel we are proposing to try is only 450. Will you please put in hand two sets of P.III gearbox gears, as per the list of piece numbers attached, and also two sets of steel Bentley timing gears to the specified piece numbers. The steels should be ordered from Messrs. Samuel Fox, and the order marked "for the attention of Mr. Bolsover, Chief Metallurgist". The gear blanks should be obtained as hand forgings, as it is doubtful if the people who have our dies at present would be capable of handling this steel. One set of the gearbox gears should be cut in the ordinary way, and ground in the soft condition, then sent to Ford's for hardening. The other set should be cut, shaved and sent to Ford's for hardening. | ||