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 to Messrs. Borg & Beck Ltd. discussing the failure of a facing and comparing Hyco and Ferodo No.6 materials.
| Identifier | ExFiles\Box 129\3\ scan0227 | |
| Date | 28th April 1936 | |
| X110 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Smth.7/KW. 28th April, 1936. Messrs. Borg & Beck Ltd., Tachbrook Road, Leamington Spa. Dear Sirs, We beg to confirm the visit which Mr. Armitage and the writer paid to Ferodo's yesterday to discuss the failure of a 13 1/2" facing in American Hyco. On considering the respective types of weave and construction used in Hyco and Ferodo "No.6", it would appear that the latter should have a considerably greater physical strength. This fact, in conjunction with the lower loop stress in "No.6" owing to its lighter weight, seems to make it probable that we shall have no trouble with "No.6" due to tearing under centrifugal loading. We are taking measurements of the tensile strength of the two materials, cutting the test pieces in several directions. We agreed that it would be an improvement to reduce the depth of the rivet heads below the surface of the facings to 1/32", and we understand that you are arranging to do this on future plates. We have not yet had time to confirm the claims made that "No.6" is very durable and we are very anxious that you should take every precaution to ensure that the depth of countersink is never less than 1/32". We beg to remind you that you have promised to let us have one set of "No.6" facings. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||