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).
Analysis of a Chromidium iron brake drum after braking tests.
| Identifier | ExFiles\Box 120\1\ scan0322 | |
| Date | 14th January 1936 | |
| CHROMIDIUM IRON BRAKE DRUM. Received 14/1/36 from Mr. Toghill after undergoing Braking tests. Thickness of Section 5M/ms. (machined) Brinell hardness No: 229. Mag: 700 dias: Etched in Picric Acid. Mag: 200 dias: Etched in Picric Acid. Mag: 100 dias: Unetched. | ||