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 Hardy Spicer & Co. discussing connecting rod forgings, including die life and tolerances.
| Identifier | ExFiles\Box 132\2\ scan0265 | |
| Date | 17th June 1940 | |
| 1119; Hardy Spicer & Co. Limited. TELEPHONE: BIRCHFIELDS 4504-9 (6 LINES) TELEGRAMS & CABLES AUTOJOINTS, BIRMINGHAM LONDON OFFICE BUSH HOUSE. ALDWYCH LONDON W.C.2 TELEPHONE: TEMPLE BAR 8219 REGISTERED OFFICE AND WORKS BIRCH ROAD, WITTON, BIRMINGHAM, 6. OUR REF. JAD.MW YOUR REF. OY3/D/. RM.{William Robotham - Chief Engineer}8.JMS 17th June, 1940 W. A.{Mr Adams} Robotham Esq. Rolls Royce Ltd. D E R B Y. Dear Mr.Robotham, re Connecting Rods. I thank you for copy of note from Olley I do not know what the life of Dies would be but the figure of 12000 forgings in 1045 includes one repair and sounds reasonable. The other details really amounting to forgings with a 2 oz. tolerance, should be easy. On the work we have so far done, we had a maximum difference of three quarters of an ounce, that is, three eighths plus and minus. We also could work to dimensions of plus and minus 1/64". I notice Oldsmobile work to double this tolerance and would observe that this is exactly the tolerance we use on all our forgings for large size joints. I take it that the balancing operations are performed not by the forger but in the engine machine shop. I understand from the note, last paragraph, that the rods referred to are forged in the normal manner whilst our efforts so far have been made partly by 'hot coined' process. The machine we have is now working all out on immediate essentials and cannot be used for further experiment. Yours faithfully, pp. HARDY, SPICER & CO. LIMITED. J.{Mr Johnson W.M.} A.{Mr Adams} DANIELL. Director. | ||