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).
Page 2 of a report detailing chemical, abrasion, tensile, and heat tests on various enameled wire samples.
| Identifier | ExFiles\Box 69\2\ scan0017 | |
| Date | 7th September 1930 guessed | |
| -2- (c) Immersion in a 20% solution of HNO3 for five hours. All samples shewed negligible effect. (2) Wires twisted together tightly and then untwisted and examined for abrasion effects on the enamel. McLeod (Swiss) - enamel scraped very slightly in one or two places but not sufficiently enough to expose the copper wire. Dudlo (U.S.A.) - C.K. Prescot - remarks as for the McLeod sample above. Concordia - OK. Connolly - remarks as for the McLeod sample above. (3) Wires tested for tensile breaking load by supporting wire against various weights. McLeod - .51 lbs Dudlo - .50 lbs Prescot - .54 lbs Concordia - .54 lbs Connolly - .56 lbs (4) Wires maintained at 150°C for four hours and then wound round a wire .030" in diameter. Enamel examined for cracks. All the samples appeared O.K. with the exception of the Prescot sample which shewed the enamel to have cracked in places. | ||