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 from Lodge Plugs Limited concerning the alloy steel used in C.9 type spark plugs.
| Identifier | ExFiles\Box 79\1\ scan0236 | |
| Date | 3rd November 1920 | |
| R.{Sir Henry Royce} 235 A (100 T.) (S.F. 846 6-8-19) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2460 C O P Y. LETTER RECEIVED FROM:- LODGE PLUGS LIMITED, RUGBY. Your Ref.-Wa{Mr Wallis}/3/NJ21120. Our Ref.- BH/EW. 3rd. November 1920. Messrs. Rolls-Royce Ltd., Nightingale Road, DERBY. Dear Sirs, LODGE PLUGS - C.9 TYPE. We are in receipt of your letter of the 2nd inst., and we have pleasure in enclosing herewith a copy of our letter of the 27th ultimo as requested. We employ a special alloysteel for the centre electrodes of our D.16 and D.20 Aero Plugs. We do not use this Steel for the C9 as it is unnecessary. Owing to the construction of the C.9 Plug we are enabled to fit a pure nickel electrode, which material is entirely satisfactory for this type of plug. The use of special alloy steel is confined to certain types of plugs where there is a consider-able tensile stress on the centre electrode, and where the electrode is subjected to severe heat. In the case of the C9 Plug there is no tensile stress on the electrode, and nothing to cause it to fracture under heat. We shall be extremely interested to know of any special alloy steel which you might care to recommend to us for the use of centre electrodes in aero plugs, as we are always interested in developments in this direction. Yours faithfully, LODGE PLUGS LIMITED, (Sgd) Bernard Hopps. DIRECTOR. | ||