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).
Test results for different friction materials at varying temperatures.
| Identifier | ExFiles\Box 37\2\ scan 004 | |
| Date | 12th December 1918 | |
| AL/MP. X.3409/ 12th. December. 1918. TEST RESULTS. Temperature up to 150° Centigrade (approx). Description of material Duration of test in mins. Area in Sq. ins. Pressure per sq. ins. Speed in ft. per min. Total Amps. Co-efficient of friction. No. 30 30. 9 10 5,000 37 .36 F.B.A. No.9 30 9 10 5,000 37 .36 F.B.A. Standard. 30 9 10 5,000 37 .36 Temperature at 500° Centigrade (approx). No. 30 3 9 10 5,000 27 .146 F.B.A. No. 9 3 9 10 5,000 39 .41 F.B.A. Standard 3 9 10 5,000 34 .293 | ||