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).
Comparison table of pressure, friction, and torque for Phantom and Spectre models.
| Identifier | ExFiles\Box 93\3\ scan0031 | |
| Date | 18th March 1935 guessed | |
| - sheet 3 - Position of Levers on N.Sch.4412. Phantom. SpectreCodename for Phantom III N.Sch's 4229 to 4404. Intensity of Pressure on Linings (New): lbs/sq" 1 33.2 26.8 Coefficient of Friction on Linings. (New) 1 .177 .176 Coefficient of Friction on Linings (Fully Worn). 4 (+.188) (x.222) .216 Max. Torque. lbs ins. 4300 3930. + Distance Washer Removed. xDistance washer not removed. | ||