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).
Instructions for the machining and treatment of Special Nitro Alloy Steel for making tappets.
| Identifier | ExFiles\Box 154a\1\ scan0118 | |
| Date | 26th November 1928 | |
| Hs.{Lord Ernest Hives - Chair} C. RHC.{R. H. Coverley - Production Engineer} C. HL. Y4469 BY/EM2/K.{Mr Kilner} 26. 11. 28. SPECIAL NITRO ALLOY STEEL. ------------------------ A quantity of material has arrived at the Works from the Firth Derihon Stampings Ltd. to make tappets E.76685. The material is in the form of 1 1/4" diameter bar 16" long. We have instructed the Stores to hand this material over to you immediately, and the following instructions should be worked to with respect to the general machining and treatment of this material:- (1) Machine to within 2 m/m all over. (2) Heat to 550°C. for three hours, and allow to cool freely in the air. (3) Machine leaving 1 m/m on parts to be hardened. (4) Protect by tinning the parts that do not require to be hard as laid down in our note BY14/G19.11.28. (5) Finish machine including grinding the parts which must be hard only. (6) Nitride. With respect to these tappets, we would like to have one complete set sent to HL. so that he can experiment with hardening same by the nitrogen process, and the remainder should be sent to the Firth Derihon for them to carry out the hardening process. BY/EM. | ||