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 a supplier regarding the decarburisation of road springs.
| Identifier | ExFiles\Box 154\2\ scan0110 | |
| Date | 14th July 1938 | |
| 1305 c. Rm.{William Robotham - Chief Engineer} c. Roy{Sir Henry Royce}/Les.{Ivan A. Leslie} c. Hs.{Lord Ernest Hives - Chair} ARUA 2424. 14th. July 1938. BY.6/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Messrs. Toledo Woodhead Springs Limited, Toledo Steel Works, Sheffield, 1. For the attention of Mr. Frank Woodhead. Dear Sirs, With reference to our discussion on road springs, I would like to emphasize certain points which I raised in the discussion in order to make clear the extreme importance of the matters in question. All rolled bar is as a result of the hot rolling operations where high temperatures are combined with direct exposure to oxygen, decarburised. This can be reduced to a considerable extent, as I have previously pointed out to different spring makers, by rolling the bar from small billet and in short lengths. I noticed that your Company had faced this particular problem by rolling in lengths of not more than 16 ft. with the result that the depth of decarburising is regular and only about 20% of the depth of decarburisation one normally encounters in spring plates. The actual figure is .003 as an average, varying from .0035 to .0025. This I consider to be a very valuable achievement, and furthermore, it indicates a determination to maintain the quality of the plate as high as possible. Whilst you have considerably reduced the actual depth to which decarburisation takes place, the fact that it still remains, constitutes a serious debit to the spring, as from our experience even .001 can be a serious factor and make a material difference to the fatigue life of the material. | ||