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 The Hoffman Manufacturing Co. Ltd. confirming specifications for Roller Follower Assemblies.
| Identifier | ExFiles\Box 153\2\ scan0275 | |
| Date | 5th April 1937 | |
| 1300. 5th April 1937. Rm {William Robotham - Chief Engineer} /FJH. {Fred J. Hardy - Chief Dev. Engineer} 13/AP. The Hoffman Manufacturing Co.Ltd., CHELMSFORD, Essex. For the attention of C.Smith Esq. Dear Sirs, We are writing to confirm our discussion of Friday last, concerning Roller Follower Assemblies for our 25/30. Steering Gear, which we have asked you to make for us. The roller in question is to our drawings F.61283/4, F.61355/6, prints of which we left with you. We tabulate below the main points concerning these rollers. (1) Assemblies, consisting of 1 roller, 2 inner races, distance piece and necessary balls to be supplied matched up as units, with distinguishing markings on each piece, tied together and in separate boxes. (2) Roller to be in S.82 material which we will supply in bar form if necessary. (3) The writer mentioned during the discussion that the depth of case hardening on the roller should be 0.060 - 0.070", and at the time the narrowest section was scaled as approximately 7/16". We have since noticed that the drawing scaled was 1 1/2 times full size and in re-considering the matter we prefer that the case should be 0.050 - 0.060". If you do not agree with this we should be glad to have your comments. The above 0.050 - 0.060" refers to the depth in the finished condition, i.e. after grinding. (4) Inner races F.61283/4 will be supplied by us in the black hardened state. All grinding to be done by you. The bore of the inners will not have serrations and will be 0.500 +- 0.0002" in the finished condition. continued | ||