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 to Brayshaw Furnaces & Tools Ltd. requesting cyanide hardening services for experimental gearbox gears, including material specifications and current heat treatment.
| Identifier | ExFiles\Box 136\4\ scan0095 | |
| Date | 8th May 1934 | |
| X2061 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}6/KW. 8th May, 1934. Messrs. Brayshaw Furnaces & Tools Ltd., MANCHESTER, 15. Dear Sirs, We are writing to ask you whether you can cyanide harden some gears for us. The gears concerned, about 6 in number, are required for an experimental motor car gearbox, and range from 4½" dia. to 2" dia. We would supply the finished machined gears and would want you to carry out the cyanide hardening as we have no facilities for doing this. The gears would be in a Nickel Chrome Steel to the following analysis :- Carbon 0.14% to 0.18% Silicon (maximum) 0.30% Manganese 0.35% to 0.45% Nickel 4.0% to 4.5% Chromium 1.0% to 1.30% Our normal heat treatment for this material with the ordinary method of carburising is as follows :- (1) Carburise at 900°C. for 4 hours. (2) Heat to 820°C. and quench in oil. (3) Heat to 760°C. and quench in oil. This gives the following minimum physical properties :- M.S. Y.P. E.{Mr Elliott - Chief Engineer} R.A. 85 tons per 75 tons per 12% 35% sq.in. sq.in. | ||