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 report for a universal gearbox synchro-mesh cone, including a diagram of surface wear and performance data tables.
| Identifier | ExFiles\Box 136\4\ scan0199 | |
| Date | 1st January 1938 guessed | |
| UNIVERSAL GEAR BOX SYNCHRO-MESH CONE TESTS B 254 DRIVING GEAR TEST MODELS B 253 CONES. DIAGRAM SHOWING WHERE CONE SURFACES HAD PICKED UP TABLE I CONE INDEX Nº | DIAMETRAL INTERFERENCE | ASSEMBLY LOAD TONS | RELEASE TORQUE LB. FT. 1 | .003 | 8.0 | 383 2 | .002 | 7.0 | 353 TABLE II CONE INDEX Nº | DIAMETRAL INTERFERENCE | ASSEMBLY LOAD TONS | RELEASE TORQUE LB. FT. 3 | .0048 | 8.0 | 440 4 | .022 | 5.5 | 300 5 | .003 | 6.0 | 300 | ||