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).
Report discussing deviations from material specifications, specifically magnesium content and hardness, in the production of bearings and bushes.
| Identifier | ExFiles\Box 115\5\ scan0178 | |
| Date | 9th November 1936 guessed | |
| -4- PART AGREE which are too hard, and they would reject them if they were above hardness figure, but if they were low they would not worry about them. Therefore, they are not keeping strictly to specification by doing this. Again on analysis they agreed that if the Magnesium was 1.05% or evenly possibly 1.1 they would not be perturbed about it, but would let the job go, as there would be no serious point in connection with this slightly high Magnesium content, but Mr. Hall stated that if the Silico-magnesium content were high then we should get a bearing which would be too hard, and would be rejected. Mr. Wheeler also stated here that they had made melts using only runners and risers, and no virgin metal, and they had just added, as a matter of practice or rule, a further 1 oz. of magnesium to each 100 lb of material melted, and had carried on producing the job. This again rather points to the fact that they do not work as strictly to the points of the specification as we are trying to do. We shall know more of this when we have the analysis of the bushes when we we have brought away, and/have also heat treated same . We were able to examine dies from which they produce bearings, and apart from the fact that they are producing a bush and not a half bearing, the method is practically identical with our own. I do not think, therefore, that there is any point in connecti | ||