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).
Continuation of a letter from Wellworthy Piston Rings regarding hardness testing methods.
| Identifier | ExFiles\Box 116\1\ scan0076 | |
| Date | 23th July 1937 guessed | |
| WELLWORTHY PISTON RINGS LIMITED CONTINUATION No 1. results, that is whether it should be by Brinell or any other machine, and whether it should be by 5 mm. diameter ball or 10 mm. Yours faithfully, For WELLWORTHY PISTON RINGS LTD., F Bleacknill Technical Manager. | ||