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).
Graphs showing the results of spring deflection tests for three different clutch discs.
| Identifier | ExFiles\Box 129\3\ scan0152 | |
| Date | 29th July 1936 | |
| BORG AND BECK CLUTCH TESTS. SPRING DEFLECTION TESTS. DIA OF DISCS 11". RAD OF MEASURING ARM 3". DEFLN - INS. LOAD - LBS-FT. DISC Nº27. DISC A 11. DISC B 11. | ||