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 Ferodo Limited detailing the results of tensile strength tests on Ferodo 'No.6' and Raybestos 'Hyco' material samples.
| Identifier | ExFiles\Box 141\1\ scan0130 | |
| Date | 30th April 1936 | |
| X118D Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Smth.20/KW. 30th April, 1936. J.N. Longley Esq., Messrs. Ferodo Limited, Chapel-en-le-Frith. Dear Mr. Longley, Thank you for returning the Raybestos disc which we left behind last Monday. We have now found the tensile strength of samples (5.50" x .77" x .13") cut from an American Hyco and a "No.6" disc. In the former case we took two samples parallel to the warp which was visible on one side of the disc, and two parallel to the weft. Since the directions of the weave on the two sides were at approximately 45° to each other we cannot be sure that we have measured in the weakest direction. In the case of the "No.6", we took two pairs of parallel samples at right angles to each other. One of the samples included the joint. We give below the test results - | Material | Sample | Tensile Strength (lbs/sq.in.) | Remarks | | :--- | :--- | :--- | :--- | | Ferodo "No.6" | A | 1843 | Across Joint | | | B | 1954 | | | | C | 1957 | | | | D | 2082 | | | Raybestos "Hyco" | E | 2436 | Parallel to warp | | | F | 2105 | Parallel to warp | | | G | 1752 | Parallel to weft | | | H | 1739 | Parallel to weft | | ||