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).
Required Brinell hardness and machining difficulties for crankshafts made of .4 carbon steel.
| Identifier | ExFiles\Box 123\5\ scan0325 | |
| Date | 23th February 1939 | |
| HPS.{Horace Percy Smith - Experimental Factory Mgr} [strikethrough] RHG. [strikethrough] Rm.{William Robotham - Chief Engineer} ROY{Sir Henry Royce} [strikethrough] Cgh{W Clough}/EM. [strikethrough] 1044 BY.5/G.23.2.39. CRANKSHAFTS IN .4 CARBON STEEL. HPS.{Horace Percy Smith - Experimental Factory Mgr}5/VS.{J. Vickers}16.2.39. As explained on the telephone the 321 brinell for the .4 Carbon steel is a necessary part of the proposal. At this figure the condition of the material is such as not to be likely to cause tearing, this being a characteristic of .4 carbon steel at the brinell in question. If we lower the brinell we shall undoubtedly find that the shafts would wear at an undue rate. My view is that the apparent difficulty of machining is due to not having used the optimum face and rake angles on the tools. I have therefore arranged that Mr. Talbot shall obtain a piece of bar material in .4 carbon, give it the treatment we have given the cranks, and then supply this to HPS.{Horace Percy Smith - Experimental Factory Mgr} for the Works to do some experimental work on same in regard to tool angles. I think a reasonable length of bar is required for the experiment, and Cgh{W Clough}/EM. will order sufficient length of material there is known to be available. BY.{R.W. Bailey - Chief Engineer} | ||