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).
Letter from Ferodo Limited detailing the properties and advantages of their bonded asbestos brake linings.
| Identifier | ExFiles\Box 141\3\ scan0235 | |
| Date | 20th December 1933 guessed | |
| From FERODO LIMITED. Sheet No. 2 Messrs. Rolls-Royce Ltd., Derby. any disadvantage worth speaking of would obtain if you revert to Ferodo Bonded Asbestos - at the most there would be a small reduction in braking power for a given pedal pressure and perhaps a difference of 2,000 miles in the full service of the lining. Against this, the probable elimination of squealing and greater effectiveness after car washing may be regarded as fully compensatory. Here we may add that the present-day Ferodo Bonded Asbestos is a very much improved product and we have not the slightest hesitation in recommending it to you, particularly for use with cast alloy drums. In reply to your request for information by telephone to-day, we have pleasure in advising as follows - EXPANSION. Up to 500° F M.R. does not appreciably increase in thickness up to 1/4" thickness. At 500° F Ferodo Bonded Asbestos Die-pressed expands .008/.010" on 1/4" thickness. Specific heat of M.R. 0.24; specific heat of Ferodo Bonded Asbestos 0.341. Conductivity is in the reverse ratio of the specific heat. By another post we will send a diagram showing the rate of heat conductivity of Ferodo Bonded Asbestos in relation to brake drum temperature. This may give the information you require, perhaps in a clearer form than the specific heat values. Yours faithfully, FERODO LIMITED. E.J. Field CHIEF ENGINEER. | ||