Letter from Cadillac Motor Car Company discussing cast iron brake drums and providing a preferred material specification.
| Identifier | ExFiles\Box 170\2\ img032 | |
| Date | 3rd April 1931 | |
| Handwritten note: Hs {Lord Ernest Hives - Chair} /Row many thanks. The C.I. seems to be the Bramitec as you say. By the way I notice you have written a number of notes on the back of 2nd page on radiators. I mention it in case you have lost them. Bg Printed text: CADILLAC AND LASALLE MOTOR CARS CADILLAC MOTOR CAR COMPANY DETROIT, MICHIGAN April 3, 1931. Mr. E. {Mr Elliott - Chief Engineer} W. Hives, Rolls Royce, Limited, Derby, England. Dear Hives: Re. Cast Iron Brake Drums Replying to Hs {Lord Ernest Hives - Chair} /G.W.H./ of April 1, 1931. (1) Am sending under separate cover a small sample of C.I. brake drum which may be useful. (2) Have discussed with our laboratory, the specification which Mr. Hancock sent. Criticism of this is: (a) Total carbon too high. Combined carbon O.K. (b) Silicon O.K. (c) Phosphorus too high. (d) Not enough total alloy to get required physicals. (3) Preferred specification is: Total carbon - 2.20 Combined carbon - .60 Silicon - 2.2 - 2.6 (wide variations permissible.) Phosphorus - Max. .20 Manganese - .30 - .50 Molybdenum - .50 - Tensile - 50,000 lbs. per sq. inch. Transverse break 1 1/4" dia. cast bar 12" centers 5000 - 7000 lbs. Modulus of elasticity - about 15 million. (4) A white iron is used as a base and remelted in the electric furnace with addition of final graphite and silicon, I understand in the ladle. | ||
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).