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).
Graph showing the results of a torsion test on a 20 HP crankshaft, charting its stiffness through various manufacturing stages from forging to the finished shaft.
| Identifier | ExFiles\Box 6\1\ 01-page102 | |
| Date | 1st December 1927 | |
| FORGING DIMENSIONS (AVERAGE) A | 2·375 | JOURNALS B | 1·900 | CRANKPINS C | 1·100 | WEB (THICK) D | 1·350 | TO INSIDE FLASH E | 1·200 | OUTSIDE FLASH F | 2·550 | WEB WIDTH G | 4·625 | CRANK 2·250 | CRANK RADIUS 20 H.P. CRANKSHAFT — TORSION TEST — FORGING TO FINISHED SHAFT GRAPH I Key to Operations: ① As FORGED ② JOURNALS TURNED FROM 2·375 DIA TO 2·200 DIA WEBS 1·015 THICK ③ CRANKPINS FROM 1·900 TO 1·625 DIA WEBS ·805 THICK ④ JOURNALS REDUCED FROM 2·200 TO 2·030 DIA ⑤ JOURNALS BORED 1·250 DIA ⑥ WEBS PROFILED FROM 2·550 WIDE (FORGED) TO 2·200 WIDE ⑦ CRANKPINS REDUCED FROM 1·625 TO 1·530 DIA ⑧ CRANKPINS BORED ·750 DIA (FINISHED) Graph Annotations: PERCENTAGE REDUCTION IN STIFFNESS PER OP IS 35% 35% 7% 10·5% 18% 6% 6% Axes Labels: Vertical Axis: TORQUE ON NOSE — LBS FT Horizontal Axis: ANGULAR DEFLECTION — DEGREES | ||