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 a supplier discussing the hardness and case depth of a steering gear roller component.
| Identifier | ExFiles\Box 153\2\ scan0080 | |
| Date | 7th August 1936 | |
| London Office: 17, VICTORIA STREET, WESTMINSTER, S. W. 1. Telephone: ABBEY 3875 (2 LINES) Telegrams: OFFISLUNDA, SOWEST, LONDON Branch Offices: LONDON, BIRMINGHAM, MANCHESTER, LEEDS, NOTTINGHAM AND- BALL & ROLLER R&M BEARINGS Contractors to H.M. Admiralty, War Office, Air Ministry, Colonial Offices &c. RANSOME & MARLES BEARING Co., LTD., MANUFACTURERS OF BALL & ROLLER BEARINGS NEWARK ON TRENT. Our Ref. Tech. Dept. FOH/MB. Your Ref. Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}9/JH. Telegraphic Address: "BEARINGS, NEWARK" Telegraphic Code: BENTLEY'S Telephone Nos: NEWARK 456-457-458-459 Branch Offices: SHEFFIELD, BRISTOL, GLASGOW, NEWCASTLE, DUBLIN, BELFAST. Messrs. Rolls Royce, Limited, D E R B Y . 7th August, 1936. Dear Sirs, STEERING GEAR ROLLER With reference to your valued communication of the 5th instant, regarding the above, we have examined the roller which is now to hand, and in the first case would point out that the hardness of the surfaces is in our opinion insufficient for the duty present. We ourselves should consider that a Rockwell of 60. C. should be present, and while we have not yet tested this for the actual figure, we should say from our preliminary test that the component in question is as low as 50.C. on the tracks and in certain portions of the tooth form also, and in general, we consider that the hardness all over is not satisfactory for the duty. We note also from your detail drawings that you call for a case depth of .031" whereas we should consider that .060" should be the absolute minimum case for this or any job of this type, and in the parts which we shall manufacture, we would point out that we shall obtain a hardness of Rockwell 60.C. and a minimum case depth of .060". | ||