On Wraith road springs, detailing the dangers of re-heat treating plated springs due to metal penetration.
| Identifier | ExFiles\Box 9\5\ 05-page015 | |
| Date | 29th October 1936 | |
| Rm. {William Robotham - Chief Engineer} 404 BY.6/G.29.10.36. 646, WRAITH - ROAD SPRINGS. ----------------- Further to BY {R.W. Bailey - Chief Engineer} /Cgh. {W Clough} 7/W.27.10.36. it is a very dangerous practice to attempt to re-heat treat springs which have been plated, the effect is that if the piece is bent with the material at high temperature, the molten metal penetrates the steel. I do not know if you were present at the discussion when Major Bulman was here, and Mr. Wood referred to certain experiments which he had seen done at the R.A.E., where mild steel tubes were split merely due to the presence of solder and the attendant stress due to bending the part under high temperature in contact with the solder. Even if you attempt to remove the cadmium by etching the steel, here again you have a serious problem intervening, as the acid etch is very liable to create intercrystalline penetration. This again would mean that the above would not be removed by further heat treatment, and the springs would be liable to failure. BY. {R.W. Bailey - Chief Engineer} | ||
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).