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).
The material properties of cast iron brake drums and a recommendation to machine and test samples from Leys Malleable Castings Co.
| Identifier | ExFiles\Box 120\1\ scan0136 | |
| Date | 21th December 1934 | |
| Hs.{Lord Ernest Hives - Chair} +4612 BY/EM.4/J.21.12.34. [Signature] OK COPY. CAST IRON BRAKE DRUMS. We are now in receipt of a report from our Laboratory in regard to certain samples of material submitted by Messrs. Leys Malleable Castings Co. Limited and we find that the test figures quoted by them are fully borne out in the test bars submitted to us. This material gives a brinell hardness of 187 and a tensile strength of approximately 37 tons per square inch. This is of course considerably softer, but much stronger than the cast iron we are now using for this purpose. We understand from Messrs. Leys Limited, that tests carried out by Messrs. Ferodo Limited, indicated that the wearing qualities of the material are as good as those obtained from the usual types of cast iron and Ley's material should be free from the graphite trouble since any graphite in their iron is of a secondary nature and formed by heat treatment and is not present in the material as cast. After discussing this matter with Messrs. Ley's representatives, we feel satisfied that this material does possess certain characteristics which are likely to be of value for a brake drum material and we therefore recommend that the brake drums which we understand Messrs. Leys Limited, have already supplied to you should be machined and tried out. They are also willing to supply any further drums which we may require for test. BY [Signature] | ||