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).
Comparison of standard and experimental solder compositions for commutators, noting their different melting points.
| Identifier | ExFiles\Box 62\3\ scan0166 | |
| Date | 31th January 1931 | |
| X6066 31.1.31. X.6090. COMMUTATOR SOLDER OF 14° HIGHER MELTING POINT THAN STANDARD. The solder at present standard for commutator connections is constituted as follows :- 66 2/3% Sn.{Mr Sanderson} 33 1/3% Pb. and has a melting point of 184°C. This proportion constitutes a eutectic i.e. an alloy of the lowest melting point. The proportions in the experiment solder are as follows :- 55% Sn.{Mr Sanderson} 45% Pb. and has a melting point of 198°C. EFC. | ||