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).
Redesign and standardization of plain washers for aero engines and motor cars.
| Identifier | WestWitteringFiles\A\December1917\ Scan3 | |
| Date | 22th December 1917 | |
| By.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} C. to H.{Arthur M. Hanbury - Head Complaints} C. to Oy. C. to Bj. X3 ORIGINAL X.1906. R1/W22.12.17. 3 RECEIVED 27 DEC 1917 Re - Plain Washers for Aero Engines and Motor Car Work. I am quite in agreement with a scheme of altering these to a lighter pattern which is not so large in external diameter, possibly also thinner. I have noticed on the Calcott car that the washers are a much closer fit to the bolt and thinner and smaller in external diameter. so that it could not be considered 'faddy" for us to adopt a lighter pattern for such important work as aero engines. In addition to remarks made on your scheme 246, I should suggest that we particularly looked into the question of the fit of the hole, that is, I should have a certain percentage of clearance as a minimum with a percentage as a maximum, because we do not want these small washers to get out of centre much. For external diameter I should use a constant formula, such as - d x 1.6 + .05 -- D.{John DeLooze - Company Secretary} One would think also that the thickness should vary and that the list should go up to 1/8", 1/4". It should include 5, 3, 2, 1, BA. 1/4", 5/16, 3/8, 7/16, 1/2", 9/16, 5/8, and 3/4", so that there shall be no doubt if anyone wants to adopt any of these sizes what size of washer shall be drawn. There are also some little corrections to make to the smaller nuts. We shall be glad if you will look into this matter and say what your suggestions are for the convenience of spanners, stock sheet metal, etc., R.{Sir Henry Royce} | ||