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).
Specification document for clutch thrust springs.
| Identifier | ExFiles\Box 129\3\ scan0360 | |
| Date | 13th August 1936 | |
| 1110 CLUTCH THRUST SPRINGS. Gauge 8 SWG. .160 Inside dia. (Parallel) .805 Tot. Coils 8 1/2 Free coils 7 Grind 3/4 coil each end Make 9 with free length 2.880 " 9 " " " " 2.660 F.{Mr Friese} Ll. Smith. | ||