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. Ltd. discussing joint hardness specifications and measurements.
| Identifier | ExFiles\Box 148\4\ scan0083 | |
| Date | 6th October 1938 | |
| 1262. HARDY SPICER & CO,. LIMITED. TELEPHONE : BIRCHFIELDS 4504-9. 6 LINES TELEGRAMS & CABLES : AUTOJOINTS, BIRMINGHAM CODE : BENTLEY'S PHRAZE LONDON OFFICE. 64. ST THOMAS STREET LONDON - S.E.1 TELEPHONE : HOP 0703 OUR REF. JAD.MW YOUR REF. RM.{William Robotham - Chief Engineer}GRY.{Shadwell Grylls}12/MH{M. Huckerby} Manufacturers of HARDY SPICER UNIVERSAL JOINTS AND PROPELLER SHAFTS • GENUINE HARDY FLEXIBLE COUPLINGS. BRITISH BOUND BROOK OIL-LESS & COMPO OIL-RETAINING BEARINGS ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY Registered Office and Works BIRCH ROAD . WITTON BIRMINGHAM·6 ENGLAND 6th October, 1938. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} H.{Arthur M. Hanbury - Head Complaints} Grylls Esq. Rolls-Royce Limited. DERBY. Dear Mr.Grylls, I regret that yours of 14th ult. has been unanswered. This is due mainly to my absence, having just completed a trip in Scandinavia. To deal with the Specification, I would say that the hardness should be Rockwell 'C' 59/62 and the depth .040 - .050. Our measurements of the hardness of the sample vary between 57/62, and the depth is .035. I would say that the 57 hardness is on the side where it is damaged the top where the thrust is taken is up to 62. These specifications have proved very successful and if you could read into the slight difference between our specification and the sample, the cause of the trouble, I shall be prepared to let it go. To me however the difference is so small that I would rather think that the duty to which it has been put is unsuitable for the particular joint. Perhaps when I meet you next you will be able to tell me more about the tests upon which you have previously reported a failure, and I gather that your own joint does not stand indefinitely, but apparently has a longer life than ours. From what I remember of your joint, it has a larger capacity and it may be that this difference gives a longer life. I should like to see you again some time -1- | ||