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 from its initial forging to the finished shaft.
| Identifier | WestWitteringFiles\R\2December1927-February1928\ Scan032 | |
| Date | 6th December 1927 | |
| FORGING DIMENSIONS. (AVERAGE) A.{Mr Adams} 2.375" JOURNALS. B. 1.900" CRANKPINS C. 1.100" WEB (THICK) D.{John DeLooze - Company Secretary} 1.350" TO INSIDE FLASH. E.{Mr Elliott - Chief Engineer} 1.200" OUTSIDE FLASH. F.{Mr Friese} 2.550" WEB WIDTH. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 4.625" CRANK. 2.250" CRANK RADIUS 20 H.P. CRANKSHAFT. - TORSION TEST. - FORGING TO FINISHED SHAFT. GRAPH I TORQUE ON NOSE - LBS. FT. ANGULAR DEFECTION - DEGREES. 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) PERCENTAGE REDUCTION IN STIFFNESS PER OP. 32.5% 35% 7% 10.5% 18% 6% 6% | ||